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Mouthfill Techniques


Umberto uses Frenzel to equalise to 120m (inverted, Variable) and then a Valsalva at about 135 which takes him to 150 (No Limits). He has very little trouble equalising CW, due to incredible diaphragm control, and I suspect he is mouthfilling as well.

I don't think Pelo even packs when he goes on holiday...


Back in 1998, I had spoken with several divers who had competed in Sardinia. I was asking about deep equalizing techniques. Several divers used a 'mouthfill' method which involved filling the mouth up each time you tried to equalize. Among those divers was Australian Tony Heugh, who explained to me how he would fill his mouth up with air each time he tried to equalize.

I was doing a chi-gong standing meditation around October of '98 when an idea popped in my mind. All of my ideas come to me during chi-gong standing meditation (the fluid goggle idea came during such a meditation).

It occurred to me that one might benefit by filling the mouth only ONCE, at the maximum depth which one could fill the cheeks completely. When this idea came to me, it was not at all obvious that a single mouthfill method would have any advantage over current techniques, including the 'repeated mouthfill' method. I tried to do many calculations but at the time I didn't understand enough about the various airspaces to conclusively decide whether or not the technique would be helpful.

Further, I was uncertain if it was even possible to trap air in the mouth and equalize with the throat still closed (epiglottis closed). I didn't understand enough about the anatomy of the nose and throat to figure that out.

Eventually I began doing experiments, and at first it seemed that it was impossible to do the standard frenzel with the throat closed. However, after many hours of practice, I found that it was in fact possible, but it was simply a reflex to raise the soft palate whenever you close your epiglottis. Eventually I 'de-trained' that reflex after many hours of practice. At the time I had never heard of anyone else spending 3+ hours a day on the couch trying to detrain a throat reflex, so I began to wonder if anyone had done this before. I thought that if this technique really did offer an advantage, then surely someone must have thought of it before. The fact that I had never heard of anyone doing a single mouthfill made me think that the technique could not possibly offer any advantage over existing techniques.

Mayol himself described the extreme effort it would take to 'force' air into his ears while trying to equalize head-down on his 80m+ dives. This alone told me that he had not used a single-mouthfill technique.

Anyway, it was not until early 1999 that I took a trip to Alouette lake to test out the technique for real. At first I tried filling my mouth at the surface and then doing negatives. I quickly found out that performing the technique in the water, with so many other things to think about, was not easy, and I kept losing my mouthfill or my soft palate would lock up. Eventually I managed to do it on negative dives.

Then I tried a dive where I filled my mouth up at about 10m and continued down to 22m. I was amazed that when I got to the bottom, my mouth was still full of air. I sensed that the technique might actually have some merit after all. This confused me even more, because by now (several months later) I had spoken to many more divers about equalizing techniques and still none had ever mentioned a 'single-mouthfill' technique although many had spoken about repeated mouthfills or reverse packing, diaphragmatic frenzel, continuous valsalva, saline equalizing, etc...

I competed in Nice, France in 2000 and did several 67m dives, but I didn't feel the need to do the mouthfill and instead relied on the diaphragmatic frenzel, which I found I could still do with little difficulty at 65m+. After the competition was over I had a long talk with Herbert Nitsch about equalizing techniques. I explained my 'single-mouthfill' technique to him, even though I didn't actually use it at the competition. He told me that he had tried the repeated mouthfill and reverse packing methods before, but he had not heard of the single mouthfill -- and like most people, the idea that a single mouthfill at 30m could last you until 100m+ seemed ridiculous.

It was not until I was training for the CW record in 2001 that I found out how much energy I saved by filling my mouth at 30m and then never doing any effort until the bottom. It allowed me to sleep during the descent, and I saved a ton of energy. The descent became a joke. The ascent was the whole dive.

It was during that time, June 2001, that Herbert was training for the CW record in the Austrian lake. I had been chatting over e-mail about how much energy I was saving by doing the single-mouthfill. Unfortunately it is so hard to learn that Herbert hadn't been able to do it yet. Equalizing was his limit and although he was aiming for 82m, he ended up with a 72m record.

Two months later I did my personal best of 88m and found that even after equalizing at the bottom I found that my mouth still had air left for more equalizations, ultimate proof, for me, that this technique did offer an advantage.

I did the 82m record and then eventually decided not to go to Ibiza. However, when Herbert congratulated me on my 82m record I spent some more time chatting with him about the single-mouthfill method, and I told Herbert not to give up. During training in Ibiza he finally figured it out and did 89m, followed by 86m during the competition, breaking my short-lived 82m dive which had only passed 'official' ratification the night before.

At that point I had some mixed emotions. I wondered about my philosophy of sharing techniques. The selfish part of me said that if I never shared techniques, perhaps I would still hold the record! Then, I figured that I would get good karma by sharing and good things would happen eventually.

I had also been chatting with Patrick Musimu. Early the next year (2002) he was trying for the CW record with the IAFD. He had a personal best of 79m and was limited by equalizing. Pipin was trying to teach Patrick the sinus flooding technique, which Patrick tried, but he found he got very dizzy and disoriented, since he was not on a sled. I kept e-mailing Patrick during the days before the record, offering more detailed explanations than are given in the document on my website. Patrick then did his 87m record with ease, and told me that three days before, he had gone out into shallow water with Isabel and finally figured out how to do the single-mouthfill.

So, when faced with the question, was anyone doing the single-mouthfill technique before 1998? I suppose we can never say for sure. Unfortunately when people say 'mouthfill' technique, almost everyone thinks of the 'repeated mouthfill' technique, and people like Dieter Baumann say 'oh, I've been filling my mouth since the 70's.' Unfortunately it isn't the same technique. Dieter was Herbert's coach during his 72m lake record where Herbert missed his target of 82m due to equalizing. I felt like asking Dieter why he didn't teach Herbert the 'mouthfill' technique back then.

What I can say is that so far, of the people who are currently doing the single-mouthfill technique, none are doing it very efficiently. Herbert still broke his eardrum in Cyprus despite the mouthfill technique. Musimu himself said he thought he could maybe make 95m with the mouthfill. However, if done properly it will get you far, far deeper.

Currently my personal best for a negative dive, filling my mouth at the surface, using a sphera mask, is 32.8m. With a full pack, I can get a full mouthfill at 35m with great effort.

Doing the math:

negative dive:

0m to 32.8m = 1atm to 4.28m = 4.28x

Mouthfill @ 35m = 4.5atm

4.5atm * 4.28 = 19.26atm = 182.6m

So, if I were to fill my mouth at 35m with the same efficiency as I did on the 32.8m negative dive, using the sphera mask, I would reach 182.6m, head-down, equalizing with a mask. Now THAT is an example of an efficient mouthfill.

If someone like Hubert Maier with 14L lungs did it that efficiently, he could probably get to 200m+ with a mask!

Eric's Frezel-Fattah

Extension of Eric's work

Hands-free Equalization

Hands-free Equalization


This may really be helpful, I have been practicing this for decades!

It takes a few careful tries until You get the feeling.

Starting from the surface going down, I allow a little pressure to build up in my mask very carefully. While I compensate my mask, moving my jaw a little bit, I take advantage of the pressurized air that is now escaping into my tubes (moving of the jaws facilitates the opening of the tubes). If You can equalize very easy by pinching Your nose You should not have any problems with the "mask-technique". As I continue to equalize, the mask is kept away from squeezing my face and at the same time the tube is acting like a valve, opening up at every blow into the mask.

I am not sure if the connection between mouth and lungs (epiglotis) has to be shut while You do it (I will check it out next time when I go diving). This technique as helped me to go -30m/plus in unassisted constant ballast (constant weight without fins) and added a lot of joy in freediving. However I am limited to a maximum of -40mt that way (with the last equalization around -36mt).

For maximum dives I have to resort to the newly acquired frenzel/fattah method. How I was able to apply this technique successfully, even though I failed in some of the exercises prescribed in effatah's famous document,


Same way I discovered I could do it. I was priming my throat muscles to do a Frenzel, and it just happened. I felt like I won the lottery . Best way I can recommend to get hold of those hard-to-reach muscles is to pretend your listening to the mother-in-law go on about her new plans to decorate her house. In other words, practice yawning while keeping your mouth closed . Next time you feel a yawn, listen to the 'rumbling', [sometimes] followed by the gentle pop in your ears. That's the sound of success. When you can access these muscles, and make that same sound at will, you're on your way. To finally make it work for you underwater may require a tongue thrust, jaw wiggle, or stronger muscles. Everyone is different. That's the best I know how to teach this esoteric technique.


You can try -SBT- "skindiver's back-pressure technique"

You simply use the back pressure / ( high pressure) of the mask and equalise against that. Push it against your face to help it to seal whils't learning if you must and strap it quite tightly. You will learn how loose you can make it before leaking air foils your SBT attempt.

1 ) Simulate the clicking that you hear in your ears when you yawn.

2) Hold the tubes open. *

3) Breathe out into your mask.

4) Do not not not close your throat.

5) Allow the air to enter the tubes whilst breathing out into the mask.

*You can practice holding the tubes open on land without mask by :

1) clicking ( opening up the tube)

2) holding the click ( ie do not relax the muscle once clicked)

3) Listening for your fairly hard nasal breathing in your head.**

**You will know that you are successful if you hold the click and breathe in and out through your nose and hear the air rush inside your head via your inner ear instead of outside. It sounds like a regulator delivering air on scuba.

With some observation you will find that you can actually feel your drums flex in and out with fairly exaggerated nasal breathing.

Tip: if your tubes wont open or only one opens ( common) then do a normal frenzel and then release the pressure in the ears with one click.. but hold the click and breathe in and out through your nose listening for your inner breathing.

(IIf you hear your breathing via the outside ear only, your tubes are still shut.

f you cannot get to hear your breathing in your head then you will prolly never get this right.)

Then try it in the water. Your can learn to do it on scuba much easier since the air is being delivered at ambient pressure, there is lots of it, and if your mask leaks it doesnt matter.

Then try apply what you have learned on a freedive.


What you are doing when equalizing hand free, is flexing your tensor palatini and levator palatini muscles. The only good picture of the tensor palatine muscle I have seen was at an ear specialist office. It actually wraps around the eustachian for the lower length of it. The Eustachian tube normally is closed in the lower 1/3 of its length. One of its functions is to open and allow air into the middle ear, to increase the pressure in middle ear to that of the outer ear (ear drum in the middle). The tube them closes to hold the increase air volume and pressure in the middle ear.

On your ascent the increase pressure from the middle ear is usually all that is needed to open the Eustachian tubes to let air out of the middle ear and into the thorax. The idea that it would be great to have your Eustachian tubes open all the time is a myth. This happens to some people and it is called PET. I forgot what the letters stands for, but it’s a problem that really messes up some people’s lives. The main symptom is hearings one breath in the ears. Also holding them open for a whole length of a descent is not good either, because you can over inflate your middle ear and put to much pressure on the eardrum. The best is quick and short equalizations. That way any excess air pressure will bleed out the Eustachian tube quickly and the ear will quickly equalized.

Scuba diving has two big advantages to hand free equalization. First is that the diver is usually not inverted (makes a big difference for some people). The second is that a scuba regulator, regulates the air pressure in the breathing cavities to the ambient pressure on the out side of the eardrum. All you have to do is open the eushachian tube for a split second and presto, they’re equalized!

Now in freediving, you get less than ambient, or negative pressure in the breathing cavities when at depth. This is why at extreme depths diver’s lungs actually fill with fluid and blood. This is also why it’s much harder to equalize hands free in freediving. It becomes harder and harder to push air into the eushachian tubes and middle ear without holding the nose and doing a frenzel or other technique.

I learned all this stuff by, well frankly I had too. I had a bad inverted equalization problem, although I had no problem upright and could even do it hand free. I researched it for months and purchased and practiced on an inversion machine. It took me about 8 months to master and I still have to practice twice a week. The moment I think I have it, I will have problems again.

For me the trick was to learn to flex the muscles and open the tubes before I put any air pressure on them. Any air pressure first, and they wouldn’t open when I was inverted. I learned to flex the muscles by employing the theory that if a muscle flexes, even if not by its self (firing muscle tissue) it still send signals to the brain that it is moving and you can learn that feeling and use it to learn to flex the muscle. Basic physical therapy stuff. You know were they retrain someone to use their muscles by manually moving it for them at first?

To do this I stood in front of the mirror and did the Frenzel technique several times, really concentrating on the feeling around the tubes open. Then I kept decreasing the pressure. If I lost the feeling I increased the pressure to regain it. In a few days I was able to fire the muscles and open them without any pressure. Then for inversion it was a quick mater of learning to fire and immediately pressure.

For what its worth, that’s my story. Oh I have found that packing will allow me to equalize hand free a little further down, but for me its like what jvoets said. It takes more time than just pinching the nose and going down fast. Although if I thought it was possible for me to learn to equalize hand free well enough to descend at top speed, I would certainly work on it.


It's not the 'yawning' that opens the tubes. It's after the 'yawn' that they pop. If you're keeping 'tension' on your neck, they probably won't go. It's the split second after you release the tension that the eq takes place. Practice doing that yawn technique in front of the mirror. If your doing it right, your adams apple should be pulled up. If it' not, try doing the same technique, only this time, with your tongue smashed to the top of your mouth. Now, right when you relax the muscles that are making the rumbling sound, thrust your tongue backward into your soft pallate. At this time, your adams apple will drop back to its original position, and your ears should have [simultaneously] produced a cracking sound.

If you want to simulate a dive. Pinch your nose, and suck in, until you de-equalize your ears (making the pressure lower within your eustation tubes). Then practice equalizing. Using this, you'll know for sure if your going to get it underwater. Don't do it too much though, or it can make ya dizzy with a headache.


Residual Volume Measurement Ideas




Sunday I tried to measure residual volume. On a dive to 10 meters, I exhaled completely for over 10 seconds, emptied my mouth and pinched my nose to close off the expanding mask. When I got to the surface, I measured the air that I could exhale in 10 seconds and it was 1.1 liters. Given the method used, it should be read 1.0-1.3, I think. Head down or head up didn't seem to make any difference. Does that sound like a measurement of residual?

Since my vital capacity measures 5.2-5.8 (the higher number is immediately after stretching), I can leave the surface with a total air volume of 6.4 to almost 8 and should reach residual at 43 to 56 meters with the Beuchat mask or get a complete mouthful of air at 36 to 46 meters. When I tried, the 35 meters (no packing) worked OK, but at 45, I couldn't fill my mouth. Carlos, who patiently supervised all this, commented that I lost some air on the deeper dive.

Since a full exhale plus mouth full dive to 10 meters is possible, the lungs must be able to squeeze down to about half a litre. Just thought that I would share and find out if my logic will pass review.


At 10m, once you exhale, the air which volume which remains is RV @ 2atm, so you have a total of 2RV at 1atm.

When you get to the surface, you have 2RV total in your lungs. When you exhale to the max, you exhale down to 1RV, so the amount exhale would be 1RV, so yes, it seems your method should work. Quite ingenious!

It doesn't take into account the volume of your sinuses though. If you closed your epiglottis on the descent and allowed air from the mask to fill the sinuses, it would work better. Also, it doesn't take into account blood shift, which should be quite weak for a 10m dive.

I have an additional idea.

Try this:

Do the test at 5m:

@ 5m, you exhale to RV @ 1.5atm, then upon ascending you have 1.5RV. Once you exhale down to RV, you must have exhaled 0.5RV. So double the amount you exhaled.

Do the test at 10m.

Do the test at 15m: RV @ 2.5atm, then at the surface you have 2.5RV, exhaled to 1RV, meaning you exhaled 1.5RV, so divide the amount you exhaled by 1.5.

Do the test at 20m, dividing the result by 2.

Interestingly, we see a trend:

For depth X, divide the exhaled air by X, then multiply by 10:

@ 5m: RV = ( Exhaled volume / 5 ) * 10

@ 10m: RV = ( Exhaled volume / 10 ) * 10

@ 15m: RV = ( Exhaled volume / 15 ) * 10


Then, you can graph the results, and any errors should show up in the graph.


There is another method too, but more complicated.

This method can measure both total lung capacity (TLC) and residual volume (RV), with no equipment needed!

The method is as follows:

- Get in the water with no wetsuit, and fully wet your hair

- Inhale to the max (and/or pack)

- See how much weight you need to become exactly neutrally buoyant

- Next, at the surface, inhale to the max (and/or pack)

- Go to 10m

- See how much weight you need (or how much buoyancy) you need to become totally neutral

- For exhales, same thing, exhale at the surface, see how much buoyancy you need to become neutral

- Do the same at 5m or 10m

To get an accuracy of 0.1L, you would need 0.1kg weights, and pellets with 0.1kg of buoyancy, all of which would need to be figured out before hand. However, it would be quite accurate, the only inaccuracy is the definition of 'neutral buoyancy.' The surface part should actually be done at 5m, to eliminate parts of your body breaking the surface.

You could make it even more accurate by not using neutral buoyancy, but by weighing yourself with a scale, via a cable to the surface.


- Inhale to the max, wearing a 15lb belt

- Go to 5m, have the surface operator 'weigh' you via a cable to the surface

- Go to 10m, weigh yourself again

- Go to 15m, weigh yourself again

Same for exhales.

This would be EXTREMELY accurate if the scale on the surface is accurate. You could figure out the total volume of compressible airspace in your body to within grams.


What is the need for a depth correction depending on salinity, water temperature etc. considering the following:

You probably measure all the deapths with the same deapth gauge/ computer. These machines normally use a fixed water density to calculate deapth (in the manual it mostly says that they are calibrated for salt or seawater use). Normally deapth calculation is not temperature corrected (no corrections are made in water density/ displayed deapth based on different temperatures). If you know what water density the deapth gauge/ computer uses for its calculations there is no need to do corrections for this RV calculation. For the calculation you want to know what water pressure you are at and you do not need to know the exact corrected deapth so you can skip a lot and calculate the water pressure directly. Displayed deapth * water density used by the computer model = water pressure you are at.

If you use lead to do the measurements:

I think that the lead if measured in sweet or saltwater makes no huge difference in the end result of the whole calculation due to small differences and other inaccuracies in other measurements. Just weigh what the lead that you use weighs in the water, which is less than on land, and also depends on things like if it is coated or not.

Great ideas to measure RV. Would be wonderfull to see some more experiences with the various measurements and methods.

Another idea: does the small error that the volume of the sinusses or mask make matter if you equalize them anyway? This could make these methods even more valuable than the (expensive) medical tests.


To Kars and all others who would like to measure the volume of the ears, sinuses or even the mask that needs to be equalized.

How about the following method:

Use the method of full exhale on different depths and measure the volume you can exhale again at the surface. Calculate the residual volume in the following cases:

1 when ascending close off the lungs with your epiglottis and let the air in the sinuses, mask etc escape into the water.

2 when ascending suck back into the lungs the expanding air from sinuses, mask etc. so it does not escape and can be measured.

3 dive with a noseclip or close the nose and suck the expanding air from the sinuses etc. back into the lungs so it does not escape and can be measured.

1= residual volume of the lungs

2-1= volume of the equalized sinuses+ ears+ mask

3-1= volume of the equalized sinuses+ ears

2-3= volume of the equalized mask space

I have no spirometer and therefore cannot do the measurements but am very curious what numbers anyone gets and if the volumes differ enough to be able to do the calculations.


Co2 Compartment Hypothesis


Suddenly, it dawned upon me. I'd like to introduce a concept for breath-holding which really isn't new, but should explain a lot of weird mysteries many of us have noticed while doing apnea.

Let's start with some physiology review:

- O2 has almost no solubility in water

- CO2 is very soluble in water

Because of that,

- Most of your oxygen must be stored in hemoglobin and myoglobin, and lungs

- CO2 can be dissolved in the blood plasma (i.e. blood water), as well as the rest of the water in the body

The 'bohr' effect states that the hemoglobin will only release oxygen in the presence of adequate acidity.

When CO2 dissolves in water, it creates carbonic acid, and thus acidity.

[this is all old news, just bear with me]

Thus, when you overbreathe, your CO2 level goes down, and your blood becomes very alkaline, preventing hemoglobin from releasing O2.

Further, low CO2 causes blood vessels to vasoconstrict. Vasoconstriction prevents blood flow, and thus prevents oxygen flow to vasoconstricted areas. The result is tingling fingers, fading vision, and finally hypocapnic blackout.

However, all of those effects are caused primarily by the acidity (or alkalinity) of the blood itself. By rapidly hyperventilating, you will rapidly change the acid-base balance of your blood. However, in the short term, the remaining 50kg of water in your body will not be affected. This is a huge point.

Let's divide your body water into two compartments:

- Water in the blood (i.e. blood plasma) = about 5L

- Water in the rest of the body (body water) = about 50L

As you hyperventilate, your blood water rapidly becomes alkaline, and can cause a hypocapnic blackout. This could occur even if your BODY WATER were still very acidic, and laced with CO2.

For example, suppose you finished a CO2 table and were laced with CO2. Now, you hyperventilate until your vision fades. You conclude that you have blown off all the CO2 from the CO2 table -- incorrect. Your blood is now alkaline, but your body water is still very acidic, because it takes a long time for acidity to 'diffuse' from your body water into your blood, and vice-versa.

The same effect can be seen by watching your exhaled CO2% during a CO2 table. If you do a pattern of 1'30" hold, one breath, 1'30" hold, one breath, etc., and you measure your expired CO2% on each exhale, it will quickly rise to around 7.5%, and remain there for many cycles. You assume that you are in a steady state, blowing off the same amount of CO2 that you are accumulating. In fact, the CO2 is diffusing into the body water. If you keep it up for at least 10 minutes, then, still doing the same pattern, suddenly your expired CO2 will soar to 8.0%, 8.5%, 9.0%, and 9.5% and 10% -- because now your body water is saturated with CO2 and there is no where else for the CO2 to go.

For a long time I did the following static pattern [note; hyperventilation in this context means fire breathing]

- two breaths, then inhale+pack, 3'30" static

- short recovery

- two breaths, then inhale+pack, 5'00" static

- 2'00" of hyperventilating

- Full exhale, 2'00" static

- 2'00" of hyperventilating

- Full exhale, 2'00" static

- 2'00" hyperventilating

- Full pack, 6'00" static

- 2'00" hyperventilating

- Full pack, max static, 6'30"+

The contractions would come the latest on the last breath-hold. I would feel heavily depleted from the exhale statics, and too many statics in general. However, for a reason which I didn't understand, I needed this long pattern in order to delay the contractions long enough to hit a huge time. I could only hyperventilate for 2 minutes -- no more -- otherwise I would black out during packing (not to mention feel awful).

I assumed that 2 minutes of hyperventilation would 'blow off' all my CO2 (since I would get all light-headed). If that were so, then it seems that a 2-minute hyperventilation on only the 2nd or 3rd breath-hold should do it, and delay the contractions as much as I needed -- but it wouldn't work. Why did I need so many cycles?

In fact, if you look at the above pattern, there is a total of 8 minutes of hyperventilation. The exhale statics are so short they don't result in CO2 accumulation. Even the 6'00" inhale static did not accumulate much CO2, as evidenced by my CO2 monitor upon exhaling.

What was really happening was that I needed 8 minutes of hyperventilation to 'blow off' the CO2 stored in my body water. Because of slow diffusion, it is impossible to blow off the body water CO2 in only 2 minutes of hyperventilation, even though those same 2 minutes caused me to nearly black out from hypocapnia.

So, this would explain why some people have great success by doing 8-minute breathe-ups, doing relatively slow, deep breathing. The breathing rate is not enough to over-alkalinize the blood (i.e. no hypocapnia blackout), but, by maintaining the blood generally alkaline, it allows a gradual blow off of the CO2 stored in the giant 50L body water supply.

So, if my hypothesis is correct, then a slow, 8 or 10 minute breathe-up, should delay the contractions far more than 2 or 3 minutes of hyperventilation to the point of dizziness.

So, to summarize:


"CO2 Compartment Hypothesis":

- Rapid hyperventilation changes the blood acidity rapidly, and does not allow the body water to equalize with the blood. Rapid hyperventilation will cause light-headedness and hypocapnia symptoms long before the body water is alkaline. In order to alkalinize the body water, the blood must be kept alkaline for a long time (10 minutes+). In order to acidify the body water, the blood must be kept acidic for a long time (10min+). Using this methodology, the athlete can choose to begin his apnea in any one of four configurations:

1. Acidic blood, alkaline body water

2. Acidic blood, acidic body water

3. Alkaline blood, alkaline body water

4. Alkaline blood, acidic body water

Each state would be reached by approximately the following pattern:

1. Acidic blood/alkaline body water = 10 minutes of slow deep breathing, followed by a 5-minute CO2 table

2. Acidic blood/acidic body water = 20-minute CO2 table

3. Alkaline blood, alkaline body water = 10 minutes of slow deep breathing

4. Alkaline blood, acidic body water = 20-minute CO2 table followed by 2 minutes of rapid hyperventilation


Application to the Real World

Given that blacking out from packing, and all hypocapnic blackouts are caused by alkaline blood, then in theory the diver could reach a very low state of total CO2 without suffering from hypocapnic problems by choosing state #1 = acidic blood, alkaline body water. In fact, the blood would not need to be acidic, just neutral. So, 10 minutes of slow deep breathing, followed by a 2 minute breath-hold, should allow the diver to inhale and pack to the max without hypocapnic symptoms. At the same time, the alkalinity of the body water would be so high that the diver would have a huge CO2 buffering capacity.


Great thinking and I'm sure you've just discovered something significant here, thanks for sharing it with us. The challenge now will be how to test and verify your thinking. I have a couple of related questions.

1. Is partial pressure differences the primary mechanisim for moving CO2 from body water->blood->lungs. With the PH of the blood simply providing a favourable/unfavourable enviroment for this transfer?

2. Does the level of O2 in the blood bonded or dissolved(I'll come back to this point) have any impact on the bodies ability to move the CO2 from body water->blood->lungs

3. In moving to a slow 10min breathe up what type of breathing pattern do you think would be optimal

FROM MY POST ABOVE - O2 in the blood bonded or dissolved

From my tech diving days we did some long deco on 50% O2 at 18m to open the "oxygen window" which allowed a secondary pathway for off gassing nitrogen. This mechanism assumed dissolved blood oxygen as well as bonded oxygen. Is a similar situation possibly relevant here. I recognise that we aren't breathing the benefits of 50% O2 but neither are we facing the nitrogen saturation levels of tech divers. .....just some thoughts

Ben Gowland

A few points:

1) CO2 is not just dissolved in blood but is also bonded to the Haemoglobin. It bonds to the outside of each of the four protein molecules in the Haemoglobin. This means that the blood store of CO2 is greater than just the plasm and cytoplasm content. I don't think this impacts your thinking much, but it means the difference between blood and body CO2 carrying capacity is not quite as big as first thought.

2) I disagree that you should be able to get the acid blood/alkaline body scenario. I agree with the other 3. With the 10 mins of deep breathing, you would of course get rid of lots of CO2, but in your mini-CO2 table, the CO2 would build up in the 'bodywater' just as much as it would in the blood. Then you would breathe off some blood CO2, gain a bit of O2 and do your breathold. This means you would end up with slightly alkaline blood and 'bodywater'.

Anyway - great stuff as always. I am sure you are on to something here. In some ways it is looking full circle - i.e. we are back to the 'breathe deeply' prep that was the done thing 10 years ago. I will defintely be thinking of how to apply this thought to my diving. I may even do a dreaded static or two.....


One thing I would note: it seems to me that the time to resaturate the body tissues back to their normal "resting state" CO2 levels would be much shorter than the initial breathing required to lower it. The circulation of the blood through the body combined with the atmospheric partial pressures of surrounding CO2 provides a really good diffusion rate to force the CO2 back into the tissues. The 5 minute CO2 tables may be too much. You may need to cut back to 3 minutes to get the optimal. This is only a thought, but I am wary to think that the time to release the CO2 is at a 1:1 ratio with the time to reabsorb it into body tissues.

I think of it this way. The removing of CO2 from the tissues through deep breathing techniques is like doing work to move a rock uphill. You are adding enough energy to the system to not only move the rock, but to overcome gravity. However, moving the rock to the bottom of the hill much less energy/time is required as gravity is adding to the movement.


Some points:

I neglected the bonding of CO2 to hemoglobin. If I'm not mistaken, only deoxygenated hemoglobin can bind CO2? Correct me if I'm wrong. Anyway, I think the total CO2 binding capacity of the hemoglobin is small compared to the body water.

Second, I'm certain that it is possible to reach acidic blood and alkaline body water. Keep in mind that when I do the 1'30"/one-breath/1'30" style CO2 table, my etCO2 is level around 7.5% for 15 minutes, before suddenly soaring to over 10% in the next five minutes -- why would it take so long? I'm getting contractions from the first few holds -- my O2 is still high, so the contractions are caused by acidic blood (and not low O2) -- yet, although my blood is acidic enough to cause contractions even at the start, it takes 15 minutes of steady state acidic to cause my etCO2 to soar.

I think it is true that the rates of diffusion differ: CO2 in the body water can only be removed by diffusion into the blood and then removal by the lungs. However, CO2 accumulates 'on-site' in the tissues/water itself. However, as long as the blood is pumping, the blood wipes away the CO2 which is produced in the tissue/water. If the blood did not pump, or if the lungs are empty, then the CO2 in the body water would accumulate extremely rapidly. However, inhale apnea causes CO2 accumulation in the body water only very slowly, because the lungs and blood can store significant CO2 (combined), and the constant flow of blood prevents accumulation of CO2 in the tissues, unless the blood itself is acidic.

This is why I think that during inhale apnea, CO2 accumulation in the body water is slow. So, if we alkaline all the fluids by 10-minutes of breathing, then do one apnea to contractions, I strongly doubt that in those 3 minutes the entire body water has been saturated with CO2. This means that the blood must be acidic while the body water is (relatively) alkaline.

Once again, the main idea is that it takes a 20-min+ CO2 table to cause etCO2 to soar.

Here is a question for the geniuses:

- We know that hyperventilating increases the total O2 store by increasing the hemoglobin oxygen saturation of VENOUS blood (i.e. from 60% to 80%) while the arterial O2 saturation remains > 98% (i.e. see Lindholm's thesis)

- The disadvantage is hypocapnia (or so we thought)

So, would it then be possible to make the body water acidic, then do rapid hyperventilation in order to increase the O2 store? If so, then the acidity of the body water would prevent hypocapnia in the later stages of the breath-hold, thus giving you the 'best of both worlds' : good CO2 level to ensure O2 release, and high O2 to start the breath-hold.

This method mimics what I currently use for deep diving; something I call the 'acidic system of diving.' The idea is to use an acid other than carbonic acid (CO2) to supply the acidity to release oxygen from the blood. By eating a diet high in acid forming foods (mainly meat / protein), the body becomes acidic (mostly from uric acid I think). In this acidic state, I can hyperventilate for a long time, pack without dizziness, and thus start with high O2, but not suffer over-alkaline blood, because even with the lack of CO2 for acid, the uric acid takes its place, keeping the blood pH in the useful zone to retain consciousness at the end of the dive. This has worked wonders in constant weight, but it sucks for static (at least for me).

Jersey Jim

Interesting you mentioned the diet to replace the carbonic acid with another form for your "acid system of diving". On the 25 minute ride home from work last night I began back on the 1-breath static pracice that I mentioned in the spring training thread. I usually forget about all statics for the 3 months between Nov. & January. What was surprising, was that I didn't get around to eating my afternoon pink grapefruit until shortly before leaving work. I was worried it would negatively affect the static. The pattern of 1:30, 1-breath, 1:30, etc., was noticably easier than last year. I feel I can progress this year to 1:35-1:40. I wonder if the ascorbic acid from the grapefruit had an impact in the manner you mentioned? As I always peel away the secondary skin & pectin, there was very little "bulk" that would require blood diversion for digestion. Although I did, and always do take vitamin E with my grapefruit, in the form of almonds. This also probably resulted in very little fiber bulk to divert blood. I found this to be surprising because my best static practices occur on an empty stomach, and this one was pretty comfortable.


This Eric theory make a lot of sense to me.

I decide to listen my brother, on how to make the beath-up for a max static, this is the pattern:

  • 6 min breath-up
  • Doing some packs every minute or 30 secs (for me 6-10)
  • Stop packing for the last 2 min of breath-up
  • Maximal performance (without packing) no special numbers, just until you can hold it anymore.
  • 8 min breathe-up (without packing)
  • Final attempt after full packing

With this method I could get my PB in the first attempt and improve it in the final.

I think this is related not only with pH but also with O2 stores.

In the CO2 movement we have to take into account that after a extreme breath-hold the venous CO2 is very low, the build-up during the apnea remain local (cell), after some minutes it start to be released to the circulation. If we remember and old study in AMA divers, the etCO2 was very low inmediatly after the dive.

I think we are still far to found "the key" but I love to see people like Eric, that is always looking for answers.

Ben Gowland

CO2 binds to haemoglobin irrespective of O2 as the sites are remote from each other, however, I do seem to remember that this is one of the mechanisms by which the bhor shift occurs. Thus the bound CO2 affects the binding site of the O2 and reduces the bond strength.

Frank's post stirred up some thoughts in my head about the time it takes to get CO2 from the body to the lungs. If memory serves (which it may not ) then it takes 5-10 minutes for a red blood cell to make a return trip from the lungs to the legs and back when at rest. This figure is more like 1 minute to the brain and back. This means that any build up of CO2 in the body would still take 2.5-5 mins to get from the legs to the lungs and once the lungs are resisting the offload of CO2 from the blood, the CO2 in the arterial blood will increase and trigger the chemoreceptors in the aorta, carotid sinuses and the medulla. I think that some simple modelling of blood flow and chemistry would go nicely here - although I don't have the time at the moment. I will certainly give it a go soon.

The thing that has been bugging me for some time about all our theories of blood acidity and O2 saturation etc is that we seem to be relying on qualitative concepts i.e. acidic blood offloads O2 better (and is worse at picking it up, don't forget). The problem with that is that it isn't refernced to the actual figures that the effect curve gives and relating these to the figures that is seen in the blood during a breathold. I know Eric and others have done some great stuff with a lot of instruments (oximeters etc) and gained some proper data. I think we could use that data more effectively if we feed it into some model.

I think this idea of Eric's is great, but I'm still not convinced that we are applying the concept correctly to human physiology. A spot of modelling might go nicely here. I don't have time to do it at present, but may well do so in a week or two. I think we could have much to gain.

bevan dewar

hi. the 4 configurations eric describes seem to make sense, but i dont know what take from it. it will help with formulating hypothises and designing experiments which could be carried out in water, but there in lies the problem for me. i wouldnt want to change my breathup routine for reasons purely academic, so i would want some empiracle evidence that one of these configurations works better for me than another. but as i see it the only way to decide this would be to try all four breathups decribed before attempting dives to progressively deeper depths, until i had reached a depth where three of the breathups had resulted in a samba. only then would i have a winner.(c.w i'm talking about). difficult to do in practice because you cant have 3 sambas in a row and expect the fourth dive to be a true reflection of anything. and if you do one of these configuration dives per day you have the problem of unknown variables entering the experiment from one day to the next. also, i think my instincts of self preservation would object to two minutes of hyperventilation before a very deep dive. do these experiments need to be done? and like this? what do you all think? short of sifting through 5000 posts of anecdotal evidance i dont see any other way. i'm thinking as i write, so i hope this makes some sence.


CONTINUE ON TO PAGE 2+ ***********




Static Relaxation


About the relaxation, I didn't give him any really specific instructions, but just described what I feel and do during a static. You sort of have to go for it on a "feeling level".

When I close my eyes I settle down inside, finding a quiet calmness, enjoyable, sometimes blissful. But the essence of it is that it's quiet and one has a feeling of sinking inside, of peace.

Try to locate that "zone" or place or feeling inside and just let it lead you deeper into more quietness. Don't try to push away thoughts that come as that will raise your level of mental activity and consequently your metabolism will also rise, burning more O2. So if thoughts, distractions or contractions (that ugly word ) come up and have a tendency to take you away from that state, don't fight them but just gently get back to that feeling. Softly drift back. Don't worry about how many times you have to get back, contractions may throw you way off. Just always gently drift back. In time the quietness will predominate and the contractions will be somewhere in the distance.

At first contractions will probably overshadow the quietness but with practice one should be able to experience the contractions while not losing that quietness, as if the two states could coexist simultaneously.

The point is that the quietness or peace or being in the "zone" is a more direct experience of our own inner awareness, and that is not limited by anything, being unbounded in nature. In theory contractions should not eclipse this experience but in actuality being a subtle and delicate perception it gets knocked around a bit because the nervous system has to be trained to experience it more directly and permanently - at least for the majority of us.

And this is one more interesting benefit of freediving: By diving into the depths, whether static or dynamics or constant, we also end up diving into our inner nature as the result of a search for more quietness and therefore less consumption of O2. If focused in this way, freediving is a very powerful spiritual technology, where "spirituality" is defined as the experience of our deeper levels of awareness or perception.


Blackout Avoidance : ATRC Test


There is a great tool for SWB prevention: I call it the ATRC test = ability to retain consciousness test. I thought I 'invented it' in early 2001, but it turns out a few other people have been using vaguely similar techniques.


Chances are that the first few times you try this you will almost certainly black out (on dry land) and crash on any nearby objects (possibly injuring yourself -- it happened to a guy here), so you must have a buddy ready to catch you when you fall!!!

Crouch down (buddy beside you), exhale fully, then RAPIDLY stand up while inhaling RAPIDLY. Continue inhaling to the max, then begin packing your lungs as fast as humanly possible. Count your packs, and pick a number that puts you within a few packs of totally full, and when repeating the test in the coming days and months, always use the same number of packs for consistency.

Once you have finished packing, remain standing (if possible), for about 15 seconds. Then, assuming you were able to remain standing, SLOWLY (!!!) exhale, SLOWLY!, through pursued lips (if you exhale rapidly you'll get a pounding headache).

If you are packing and start feeling light-headed, you may have to crouch down to avoid a blackout.

If your body is in a state which favors retention of consciousness, you should be able to do the test and remain standing, without the slightest bit of light-headedness.

A 'pass' is defined as performing the test and being able to remain standing. A 'B-type failure' is defined as having to bend over to stay conscious, but with no shaking or loss of motor control (B stands for 'blackout' type failure). An 'S-type failure' implies bending over and losing motor control and having a samba.

Here is the scale I use:

  • 10 / 10 = pass with no light-headedness
  • 9 / 10 = pass with slight light-headedness
  • 8 / 10 = pass, significant light-headedness but no danger of having to bend over
  • 7 / 10 = barely pass, vision & hearing fading, almost had to bend over
  • 6 / 10 = finished packing fully, waited several seconds, then had to bend over
  • 5 / 10 = finished packing fully, immediately had to bend over
  • 4 / 10 = half way through packing, had to bend over
  • 3 / 10 = didn't even start packing, had to bend over
  • 2 / 10 = could barely even stand up without fainting
  • 1 or less, fainted from just standing up

This test is the most remarkably accurate way to predict what will happen to you during a hypoxic (borderline) dive. If you fail (6/10 or less), then you shouldn't be getting in the water; you'll be risking your life, because you could blackout from a conservative dive, without warning.

Of course, even if you get 10/10, it doesn't mean that you can dive alone or push it, it just gives you a relative indication that you are in better shape than on days when you scored less than 10.

You'll find that adequate sleep, hydration & electrolyte balance are the most important factors to pass the test.

I have used the test almost daily for one and a half years, observing how I pass and fail based on what I eat, how I exercise etc., and I have developed special routines that put me in a 9/10 or 10/10. I have tried doing deep dives after failing the test, and during those dives I either BO'd, samba'd or had tunnel vision upon surfacing. It has been very accurate for me.

I usually do the test in the morning before going to the dive site, then again before putting my suit on.

Please remember that you must have a buddy watching you or else you could seriously injure yourself! Even with a buddy, do the test away from objects that might hurt you if you fall.

This test measures a huge number of physiological parameters, including adrenal gland function, blood pressure, hydration, cerebral hypoxia tolerance, high energy phosphate stores, nervous system excitability, etc. It is difficult to analyze them all; but the bottom line is that if you fail the test, you're in bad shape for diving.


Please be careful with this test. Do not over-pack. I didn't warm up, and packed slightly more than I usually do -- hoping to get the full effect of the test. I ended up injuring my chest which put me out for a few weeks, and I had to get chest X-rays done (for pneumothorax and pneumomediastinum). So, I strongly recommend that you pack-stretch before (gradually) and then don't over-pack!


Counter-weight System

Peeing in the wetsuit

URL [05/27]

I just flush my suit with lake water before I exit- that way I know it's water spilling on the boat deck when I take my suit off and nothing else.

As soon as you hit the water the pressure on you kidneys cause immersion diarrhesis ( Sven, spelling on that one?) and give you the urge to go.

I always make sure to tie a water bottle to my float so that I have plenty of fuel for my hotwater suit system.


[Why you should...]

The cells that line your bladder are called transitional epithelium cells (your eustation tubes are probably lined with pseudostratified columnar epithelium; that's the stuff of the respiratory system). They start out all bunched together when the bladder is empty, and are stretch thin when the bladder is full (kind of like an accordion). Although they can handle quite a stretch, with too much stress, they will be damaged and lose their ability to recoil. Overstretching can make you feel like you still need to go, even after you're empty. Better to listen to your body on this one.


There's only two types of wetsuits, those that have been peed in and those that will be. There's only two types of divers, those that pee in their wetsuits and those who lie about it. In over 20 years of diving, I have never peed in my wetsuit(!), but if I ever did, I'd probably pump seawater through by pulling the collar in and out from my neck, and the arms and legs of my shorty. Or getting upside down, and blowing bubbles into my collar (wetsuit neck-hole), making the bubbles come out the legs.

If I ever peed in my wetsuit.


I never do it myself but, I have a few observations.

Standing on the swim step it will run down and out the slit in the toe of your bootie that lets the air bubbles out on the first few dives.

If you pull your weight belt down to the hips, you won't pee in your ear (works best if your dimendions are 40" 40" 40" like me).

When you take your suit off, you'll be glad that the nylon is on the outside and you don't wear a bathing suit.

Some very good spear fishermen can load their gun while 'heating up' the suit.

Techniques: Swimming

Fin Swimming (Monofin technique)

Dolphin Swimming Techniques


Techniques: Miscellaneous

How to make air-rings




Stories & Experiences


URL [04/04/04]

my lanyard once got caught at 55m and i was unable to release it. it eventually released itself after 10-15secs and i surfaced without any problem. we changed our lanyard and rope set-up after that day.


wasn't sure exactly what happened. we only use 1kg at the bottom of the rope (freshwater), because that's enough to keep the rope tight and gives us the option of pulling up the diver and weights by hand - surprisingly effective - we can pull up a diver by hand at nearly 1m/s.

anyway, somehow i think i may have yanked the lanyard sideways making a loop in the rope or something. either that or it scooped under the weight. i'll never know for sure. anyway, the lanyard had a wrist clip which i could normally remove, but i was unable to remove it down there, due to cold fumbling fingers! i gave up trying to remove it and started swimming up with the bottom weight and then the lanyard somehow released itself. for a few seconds i thought i was really up sh** creek but by the time it had released and i had swam up to 40 i knew i was going to be ok. i tend to dive pretty conservatively. it's good to have some extra in reserve in case things go wrong. diving right up to your limit means there is no room for error... not good.

we changed the lanyard and i did the same dive again on the following day (or w/e?)... just to make sure it didn't play on my mind. we've never had a problem since.


I mostly dive spring caverns and caves, and there are lots of things to get caught up on: tree branchs, ledges, ropes and cables. I've been caught many times, as has Scott, especially when he carries his camera Sometimes you follow the wrong passageway, and it gets too tight to fit through, so you have to back up and find the right one.

Also get trapped by scuba divers some. Since these springs are popular dive sites, and they are a fairly confined area, you can't help but have encounters with them. I've had them ram me with their tanks or pin me up against a wall and not realize it. I even had one novice diver use me as his break when he couldn't control his boyancy and was sinking like a rock.... even after we had stopped sinking together, he kept holding on to me until I asked him to please let go of me. He heard me clearly underwater, and finally did get off of me.

(OK, maybe I didn't say "please"...)


I have had various entanglements, I can't even remember them all. Once I swam into a wreck some distance, and tried to exit through a different hole. Unfortunately my monofin was FAR too wide to exit the hole, and it jammed. Eventually I had to go back into the wreck and find the original entrance.

Another time, I went into a cave -- barely worth calling a cave, it was only about 1.5 feet tall, but about 4 feet wide. It took forever to slide inside (stupid move), then I realized there was not enough room to turn around. The only way out was feet first, the way I came. Of course, pushing the mono feet first causes the end to go up or down, which of course caught in the ceiling/floor. I took ages to get out, making inches at a time feet first, trying not to catch the mono as I slid through the 1.5 foot tall tunnel.

Many times I've had my lanyard 'fall' around my neck on the turn-around at the bottom. This prevents a normal mono stroke, endangering my return to the surface. It can be very hard to correct the problem with cold gloved hands.

I've also had muscle cramps right during the start of my ascent on deep recreational dives with no line. Plus, I used to lose the line really deep in the old days of lesser safety measures.

Once, I was using a scooter and I was ascending super fast from a wreck. There was an overhanging beam off the wreck which my head plowed into -- could have knocked me out completely if I had been less lucky -- after than I ascended slowly always looking up. Normally a freediver doesn't ascend fast enough to 'knock himself out' from an impact, but you motor super fast on the scooter. Actually, during my first few dives with the scooter (ascending far too fast), I would be dizzy when I got to the surface. Kirk told me it was because the inner ear cannot de-equalize fast enough on the ascent.


I've never been snagged by lines or anything like that, but have gotten my hands stuck in a fish's gills with it stuck in a hole, more than once. After several instances of very bloody fingers, I learned to use gloves that the gill rakers wouldn't penetrate and that I could slip out of.


I had a sticky moment in Blue Springs near Orlando a couple weeks ago. A scuba diver was talking about an air pocket in a side tunnel off the main spring vent down around 15 feet. (Jeff I'm sure you know the one!) Anyway, Scot Thompson and I were looking for it, but I was looking on the wrong side of the spring. I saw a hole going back under the logs, turned on the light and headed in looking for this "air pocket," I was sure it would make a good picture! Anyway needless to say that wasn't the right place, and neither was it big enoug to turn around in. Especially with me stuck to the roof due to positive boyancy at that depth! I backed out ok, after a couple nervous seconds, with my fins finding seemingly everything to catch on on the way out!


I was using my scooter and ascending next to a wreck, which has listed to one side over time, and ran smack into the smokestack, which was sticking out sideways! I think one of the bubble-blowers even got it on video.

Another time I was trying to be very streamlined and was descending pretty fast onto an old schooner. I was quite surprised to smack, head first, into the side rail of the ship- as I was looking sideways and not straight down. I heard my spine crunch and thought I had just broken my neck underwater! I was sore for a day or two, but fine. The noise was so loud that some divers near me could here the noise through their exhaust bubbles.

Another time, when I was diving with a camera instead fo a scooter, I dropped down onto a friend of mine's trimix class. His student's were coming up to their gas switch at 70' and I wanted some shots of it. I was below the group and decided that I wanted to ascend- right into the chest fo one of the weaker students. He was quite flustered and I now had my snorkel stuck in his hanress. I reached up, and untangled myself, gave my best "I'm sorry" shrug underwater to him and bolted for the surface.


I have done some pretty stupid things with caves which I have now learnt from my mistakes but I will tell my most scary one.

A few mates and myself had found a set of underwater caves in a local freshwater river. They were only about 2.5m down but there was exits and entrys everywhere underneath. We spent many days finding new paths and hiding in the cave to see who could hold their breath the longest then appear out one of the exits. One of my mates younger brothers who was considerably smaller than all of us found a very small exit, so as we were both sitting in the cave I watched he be the first one to go through and with a bit of effort he got through. I thought stuff it I will try as well and had a go, it was a very small hole and I had to squeeze fairly tight to get my chest through with my arms pointing like arrows out in front. It was only when I tried to keep going did I realise that my hips must have had more diameter than my chest because when I went to exit my hips would not move through. Naturally I started to panic and tried to reverse but I had no where to push from so at this stage I was frantically moving forward and back but I couldn't get my hips through. Luckily god was watching me this day because one of my mates adam realised I was down a while and came over, I remember his shock when he saw me he dived down grabbed my arms and yanked trying to get me out it didn't work so he went for a breath and I think he screamed out to everyone else. He came down a second time and put his feet on both side of the cave grabbed both my hands and yanked really hard which then I luckily came out with a few bad cuts on each side. i have never been so scared in my life.

Moral of the story dont swim through small gaps


unfortunately, i now have another incident to add to the list!

today i managed to get myself caught at 63. we have just started feeding the rope through a tennis ball, which is positioned about 1-2m above the target plate. i believe this is an idea that originates from Nice and is meant to stop a lanyard from interfering with the target plate. anyway, i went to the bottom, turned then suddently felt i was caught and was beginning to pull up the weight. i immediately realised that the lanyard was caught under the tennis ball, so i quickly pulled the quick release shakle with one hand and released myself and swam up free from the rope. it only added 2 seconds to my dive and made no real difference in the end, but it could have been more serious if i had difficulty in releasing the lanyard like last time (see earlier posting in this thread).

i need to contact the people who use these tennis balls to make sure i'm using it in the right way. i've used it 3-4 times now with no problem. our old system worked fine for months and months, so i'm tempted to revert back to our old system. please take this story as a warning... be very careful when using lanyards. they are good, but make extra sure they won't get caught, and above all make sure you can release the lanyard within 2 seconds using one hand, without even looking.... this is what i did today, and i surfaced without a problem and am able to tell you this story!


Lung Squeeze




Equipment General

Beginner Gear Suggestions


Put your money on a good suit... Elios seem to work well for the price: see the thread about "the custom wetsuit" (open cell & nylon lining). Is your baby and you should take care of it.

Fins: plastic to learn medium to hard (depending on your legs) long blade. I like the ezcalpez and the gara 2000/3000. Never try omer, but the reports are good. Ask a good diver to buy his old plastic ones, and once you know how to use them properly (a couple of years of good trashing) and you want to get deeper go for fiberblades.

Don't lessen the sales men: get a simple flexible snorkell, and a normal black silicon mask with transparent tempered glass (try the best shape for you). This should last for ever if proper care is taken.

Cheap botties (they get a hard time anyways) and good gloves if you can affront them (anything comfy from the DIY shop works too).

Rubber belt with "marsellaise" buckle. buy the bouckle and build the belt with 2 glued layers of an truck wheel tube (the one is inside the tyre) if $$$ are an isue.

Spend a few buck on drinks and lot's of good karma on your diving buddies to make sure they look good after you. That will be my best advice!


I would have purchased:

  • Elios 3mm or 5mm heiwa suit, smooth outside, open cell inside, high waist pants (not farmer john)
  • Matrix fins (equivalent to waterway fiberglass blades with sporasub footpockets; you should switch to a monofin once you are comfortable diving)
  • Technisub sphera mask
  • US Divers Impulse 2 snorkel (don't attach to your mask, hold in your hand)
  • Nylon weight belt with picasso 1kg weights (or home made super stretchy rubber belt; I don't like the non-stretchy rubber belts)
  • 3mm neoprene socks
  • Depth computer: no low cost reliable computers exist, try either a suunto D3 (malfunction prone), or a citizen hyperaqualand (more of a scuba computer)
  • Picasso 3mm bio-termic gloves

Eventually switch to a waterway monofin.


My first Equipment was and still is:

  • A Minima (becauce it fit exelent) but I have replace the strap.
  • About fins I have some old Cressi Frog
  • I have a Specialfins monofin (The Blue One) But I am thinking to
  • pursale a Waterway to.
  • Specialfins monofin´have the Omer footpockets that are great but tis monofin is more for Constant and not for pool or Dynamic .
  • I was thinking to pursale C4 Fins but I think I invest beter the Money to a Monofin.
  • Rubber belt and Picasso weigts (BTW Eric where can I pursale online Picasso weights?) are o.K:
  • Elios Suit Smothskin /Superelastic inside 3mm low Density
  • I have Order now a 5mm Smothskin /Open Cell low Density
  • One West 2mm for pooltraining or under the suit if the weater is very cold.


Freediving fins vs. Spearfishing fins


I can think of 3 things that could entice someone to have different fins for freediving and spearfishing. Stiffness, maneuverability, and surface swimming.

Stiffness: Optimal stiffness for cb would be for deeper water than spearfishing, thus requiring more stiffness. Even for spearfishing many people will use different stiffness of fins depending on the depth they are spearing. A fin good for spearing at 25 meters may be really tiring if you’re spending all day spearing in 10 meter deep water.

Likewise a diver may use a soft fins for dynamics because the soft fins maybe more O2 efficient in the shallow water of a pool. They may chose stiffer fins for better acceleration when spearfishing.

Maneuverability: Some people find that their C4’s with side rails are not maneuverable enough for spearfishing where they need to be able to change direction easily. Shorter fins with no side rails may work better, depending on diving style and depth.

Surface swimming: When spearfishing from shore, the ability of the fins to surface swim without fatiguing the diver maybe more important than underwater performance. After all if the diver is too exhausted from the swim to dive, it doesn’t really matter how good they perform under the water.


Fin Sizing


I would NOT buy an open heeled fin as the full foot pocket is more efficient. However, if you dive for short periods of time and then remove your fins, walk around, then get back in the water, the boot/open heel is more convenient.

If you are a 44, I would buy a 44-46 footpocket fin and use either a 3mm or 5 mm neoprene sock, whichever makes the footpocket snug but not constrictive. For the foot, both 3mm and 5 mm will provide thermal protection, but neither will be too hot unless you are diving very warm water. The sock also makes the fin more comfortable.

The only drawback to socks - it is not a good idea to walk in them, especially over rocks, etc. as they do not have a rubber sole. You can solve this cheaply by using an enexpensive pair of mesh surf shoes - available at Kmart, Walmart-type stores - for less than $10. Just buy them plenty large.

Brands of fins - largely a personal choice. I use Picasso because my feet are wide. Omer fins are quite nice as well, but have a different feel than Picasso and narrower foot pocket. Pirate has good prices on Omer fins. Go with the brand that fits your foot best. A good friend of mine has used the same pair of Dessault's (open heel actually) to freedive and spearfish for the last 20 years and they are still going strong.


I will add a couple of points to cj's good advice. I also highly reccomend a full-foot fin. I have used both and there is no comparison. Full foot will let you go deeper and longer, period. Another thing to consider is that open heel fins have some other drawbacks.....the buckles could break at depth, leaving you with one fin to return to the surface....they create extra drag, which you do not need as a freediver.....they have a nasty habit of snagging on fishing line and shipwrecks. All these things are arguably acceptable as a scubadiver, but not to you as a freediver.

Probably the most important thing beside that, is that the footpocket is comfortable. You should be able to spend hours at a time in the water in comfort. I love my Sporasub foot pockets, which are identical to the Mares pockets. I have skinny feet. All the divers I know with these footpockets swear by them. I use the Sporasub Radical Carbon, which has a polymer coating to protect the fragile carbon, and I would NEVER go back to a plastic fin, but I got a good few years out of my plastic Cressi Garas; they were a good start for me. Plain carbon fins are too fragile for recreational diving however.

There are a few posts about fins on the forums; most people have a favourite, and everyone agrees that at the very least, they have to be comfortable. The Mares Attack and Sporasub Pure Carbon seem to have a lot of breakage problems.

Good luck, and let us know what you end up using,


Do-it-yourself Soft Weight Harness


A while back someone on this forum mentioned the possibility of making a soft weight harness from bicycle inner tube and wear it in a figure-8. I’ve been experimenting with the idea ever since and will show my latest version here for all you DIYs out there.

Material & cost:

  • Mountaint bike inner tube, 26” X 1.9-2.2, 1X 4$
  • Lead shot from scuba weight, 12lbs 25$
  • Snap shackle, 2X 40$
  • Plastic 1” D-ring, 4X 2$
  • 1” webbing, 2' 1$
  • Velcro line keepers 1$
  • Cable ties
  • Black electrical tape

The idea is to make a harness that’s comfortable, stays put even when you’re upside down, and releases when you want it to. So the inner tube is cut into 2 sections and each are filled with shot and tied off with cable ties and covered with electrical tape so there’s no sagging in the length. The tubes are then twisted around itself to shorten the length and give some tension when I wear it. This tension will be what keeps the loops from sliding right off your back when you’re gliding downward. The velcro line keeper keeps the twisting from coming undone or sliding.

The first photo shows the complete harness, unconnected. The harness is consisted of 2 parts, the weight portion and the release strap.

The second photo shows the harness connected by the release strap into 2 loops you wear like a gun holster. The release strap is in front so you or your safety can just grab it and pull.

The third photo shows the harness as worn. Note that there should be no tension on the release strap otherwise it might accidentally release. And when the release strap yanked, either one of the snap shackles will open and the tension of the rubber tube will spring the harness right off your back. The weight of the harness will also yank the second snap shackle to release it too so chances are if you pull the release strap, the weight portion will disappear before you can turn and grab it. But that’s okay. The release is the expensive part anyway.

The fourth photo shows the back view of the worn harness.

When you wear the harness it should be tight enough to pull your arms back and you walk around like a he-man baring your chest. Once you’re breathing up, face up or down, you’ll forget it’s there. And when descending you should feel the weight pressing against the top of your shoulder/neck, otherwise the harness is not tensioned enough and is liable to slip off. The only negative thing is that the release strap hovers in front of my mouth when I’m going down. Minor annoyance.

The release strap may also be made from a small line to reduce drag.

This system has been working great for me for months now. The trim is a little heavy forward so it’s nice heading down. 12lbs is sufficient for my 5mm suit and I’m neutral at 10m. If I need to wear my 7mm I just wear an additional 6lbs on my rubber weight belt.



Do-it-yourself Fluid Goggles


A few years ago I built a pair for Martin Stepanek that he used to set his 90m record for Free Immersion in the Caymans. We had NO money for the record (as you can read in Paul Kotik's great article "Reality Czech" here on Deeper Blue) so we could not afford to buy a pair of Eric's. So we decided to roll our own.

Not being an optical engineer and not wanting to become one so late in life, I decided to find someone who could help. To make a wonderful but long story short, I managed to contact one of the world foremost optical scientists at the Max Planck Institute (Why not start at the top, huh?;-).. Anyway, this wonderful gentleman took up the gauntlet and, after a bit of computer re-programming, gave me what I needed: the part number of a cheap lens that does perfect duty in Fluid Goggles.

At first, Martin was thinking about making them and selling them but more records got in the way. So recently he and I agreeed that if it would help the dive community, we would just give out the info to anyone that was interested.

You can order two of these lenses from Edmund Optical at 800 363-1992 and order 2 each of part number 45237 which is described in their Optical Catalog as "LENS PCX 20X20 UNCTD TS". This is a high density glass lens that works perfectly underwater. When they first arrived, I donned only a swimsuit, jumped in the pool, held one up to my eye and, Voila, instant almost perfect UW vision with no mask! Way Cool.

Mounted on standoffs the way I made Martin's, there is no halo/spherical abberation and the vision is wonderful. You could glue them to flat plates and that plate to standoffs but what we did was to cut some acrylic tubes into curved sections about 22m high with small notches to hold the lense edge (so they can be removed) and mounted two of these standofffs for each lens, securing them in place with non-acid based silicone (aquarium) sealant. The lenses cost $ 26.30 each.

I will attach a photo of the mounting in the goggles.

You MUST use high quality goggles with a flat front and real face to the lens. The ones in the picture are the older TYRs that I built with Martin.


Here's a link to a place where you can buy them:

[EDITOR: I updated the link so that it now works. -Cal]




The attached pics should clarify the mounting we did but please don't take this as gospel. Like the Freedive Retrieval System that Martin, Tony and I built, we are just doing what works for us and not saying that this is the only way to skin this specific cat.

The only requirements are that the lens not touch the goggles at the forward, curved apex of the lens. The gap can be infintesimal, just not touching. The goggles must be deep enough for this mount (most are). When we wear these, our eyelashes just barely brush the back of the lens but once you fill them with saline you don't notice it.

The reason that we did the mount this way was twofold:

first, the fellow that helped me on the project said that nothing should touch the lens; no adhesive, no plate, nothing. He did not like the idea of gluing the lense to anything since he said that anything that it touches becomes part of the lens optically and will change the properties; usually by adding halos etc.

Second, was that we wanted to be able to remove them since there was that tiny gap at the front and we didn't any stuff to get caught in there and we thought that we might need to clean them. (we haven't!)

So the lenses can be snapped in and out with this method but it IS pretty tricky to build! The acrylic tube it tiny and the notches are miniscule! I used a jewelers file to cut them.

To Donmoore

I hope that I didn't give the impression that I did ANY of the optical calculations!!!!! I did NOT!<G> I just found one of the best in the world to help! (remember it's not what you know but WHO you know! ;-)

I can't help you with your perscription question but I can tell you that with this lens, there is slight magnification (and like any fluid goggle there is a pretty narrow field of view) but I wear perscription glasses for neasighteness and with these lenses I can see perfectly underwater. Well, NOT perfectly since Martin can read his Stinger or D3 up close to his face but I cannot since by my age (53) one looses a lot of adapatation in our eyes. I CAN just resolve my gauge at arms length tho.


I forgot to mention that with these goggles, once they are filled with saline, you can see both under AND above the water just fine.

Like I said, there IS slight magnification and the field of view is narrow but remember that for us these specific fluid goggles were built for just one purpose: for Martin to be able to clearly see the drop line about a meter in front of him and NOT get disoriented above the water.

There are ways to make them that will work under but not above the water be we dismissed that restriction immediately because the last thing one wants on a record attempts it to become disoriented upon surfacing and look like you samba'd or something.


I don't know if I can be of any help. Remember that we made these for one purpose only; to set a record and in that case, peripheral vision, even if a glare issue, was a good thing.. Martin wants to know if there is anything near him; safety diver, boat, whatever. The vision off the lens isn't really "vision" to speak of but you would notice a mass nearby.

Also, we don't dive for fun using fluid goggles. Martin much prefers the mask for diving and wants to do all of his records with a mask until it becomes impossible for him. So far 93m+ with a mask and he can still equalize both mask and ears so it is not an issue yet.

I too prefer a black, not a clear mask for any type of diving so in that regard I might want to darken the goggles BUT remember that the field of view is much narrower than with a mask so maybe you'd want all the peripheral data you can get.. I dunno...


Worth a try. I think that if you glue the lenses to the faceplate (on the inside, convex side pointing inward towards your eye) it should work. There are optically clear epoxies, which are used to repair windshields, that should do the trick. Alternatively, if you want to make stand-offs, 3/4" PVC pipig looks like a good candidate as part of the solution since its inside diameter is just shy of 22mm

If it works, that would be the most elegant mounting system proposed so far and if the frame has some give (like a regular mask), then it would take care of the issues that are raised by small, stray bubles in the mask -- the mask would collapse inward a tiny bit as the bubbles compressed, rather than sucking your eyeballs out of their sockets like a rigid structure would.

bevan dewar

hi all. i'm going to try attach photos of my goggles. they work well, i can read my watch clearly and see people 50m away underwater(in a pool). the main problem is that i see double as the lenses are not alligned properly with each other. this could proberbly be fixed by filing down the plastic lense holders in a way that changes the angle of the lenses. or i might just use a lense over one eye and close the other. Although i'm pretty happy with them i'm still prefering to use a sphera with noseclip.(i can take it to 30m before i have to touch my nose to remove the noseclip to equilise the mask)

the plastic pipe the lense clips into is taken from a garden hose fitting. it has a 1 or 2mm narrowing/bottle-kneck which the lense butts up gainst. one of them. i used was the perfect diameter and the lense cliped in securely without the need for glue. the other one (of another brand i think) was a hairs-with to wide and so i used a bit of superglue to anchor it. i used a bit of superglue on the rim of the pipe to attach it to the inside of the goggles lense. i did a bit of experimenting to get the lenth of the pipe right, taking it out a few times to file it down. its about 9mm now, making the flat surface of the lense about 7mm of the goggle lense and just beyond the reach of my eye-lashes. bringing the lense closer to the eye seems to offer better near-field vision at the expense of the far-off(or is it the other way arround?). experiment to find the best compromise.

conveniently, the pipe comes with 3 holes down its side which allows water to enter.

and incase you cant make out from the photo i have put the lense with flat side closest to eye, convex side facing out.

dont know if this is the best method but i think it might be easier than the method using two half-pipes with notches cut into them. cheers


You get double vision from the lenses not being parallel to each other.

The first thing to check when you buy the goggles is if the front faces are flat inside and out, then put them on and get a buddy to check if the front faces are parallel to each other across with a straight edge (up and down wont matter as you can adjust this)

If the are nearly there then you can adjust them later with the nose strap and the head strap

I also put the goggles on and marked the centre of my eyes by looking straight out and drawing a cross with a chinagraph pencil to get the rough lens position

To check the lens angle in the goggles dry, put on a bright light and look at it through the fitted lenses and you will see one big dot (hopefully)

or you can adjust to get one big dot with the straps and moving each goggle on your face


Ordinary soft contact lenses have almost no power underwater due to the fact that their refractive index is close to water. The net power underwater that you need is about +45 to +60D. However, to my knowledge bausch & lomb soft scleral contacts have a +200D power outside of the water, which drops to +45D or +60D in the water.

An almost identical discussion thread as this one passed along mark barville's 'freedivelist' e-mail list back in September 1998, during the early days of the fluid goggles (which, at the time, we called 'saline goggles'). I was repeatedly flamed on the list for 'stupid and irrelevant ideas' which had 'nothing to do with diving.' People thought that the fluid goggles were a 'joke' which 'couldn't possibly work.' Even famous trainer Rudi Castineyra (trainer of Yasemin & Tanya), didn't believe that the goggles would work until I sent him a prototype!

bevan dewar

an update on my ever improving design: i was having a small problem with bubbles collecting between the lense of the goggle and the optical lense i had mounted on the outside of the goggle lense. didnt know whether to make more holes in the black plastic 'pipe' i had mounted the optical lenses inside, which would allow a freer flow of water, or to totaly seel it up, perminently trapping water inside.

what i did instead was remove the pipe till i had a normal pair of swimming goggles again, the with a red hot screwdriver i melted a nice neat hole in the front of each lense, of the diameter of the plastic pipe. i then wedged the pipes into the holes, securing it with a bit of superglue and plumbers putty. a new photo wont show much cause they look much the same as before, except they are now missing the plastic lense that previously came between the eye and the glass optical lense. the optical lense can now be cleaned from both sides. and not having to look through two lenses seems like it may even have improved the optical characteristics slightly.



************* Low-volume masks and their volume & FOV measurements.

Equipment: SpareAir


Jersey Jim

Tanteh, I started using a spareair last summer for freediving when I got my scooter. With a scooter it is very easy to cover much more distance without effort. However, if you find yourself in a situation where you "NEED" that scooter to finish the dive safely, and something goes wrong with it, then the spareair bails you out.

The important thing to realize is "WHEN" you will need the spareair, before you are actually in danger. I guess what I mean is, that kicking to the surface in an out of air situation will not give you time to realize you need the air. It will hit you too suddenly. Like when you suspect there is a good chance your car will not make it to the next gas station. But you really think you will make it there. When your car starts to sputter, you had no idea when to predict exactly when, where and IF it was going to happen. But the instant sputtering begins, is when you black out with no time to pull your spareair out of its holster to breathe from. IT IS TOO LATE! Game over.

The important thing is to know your limits and to recognize when a dive will not finish smoothly with a margin of safety. This awareness should not happen on the way up, but a little voice in your head tips you off before you head for the surface. Maybe you know you stayed a little too long, or you were a little too deep. Or perhaps you tangled a fin on some fishing line and it took precious moments to free yourself before heading to the surface. These few moments of panic will burn even more O2 than the time you weren't calm. So don't be fooled into rationalizing that "I was only tangled for 10 seconds". Maybe you burned 30 or more seconds of O2 from the adrenalin.

Whenever you have the notion that the finish of the dive will be marginal, THAT is the time to admit to yourself you screwed up and to use the bottle. Then you must ascend slower than when freediving, and make a safety stop if possible. This is why it's also important to practice with your bottle. I have made it a point at the end of the day to "drill" and become familiar and comfortable with it. The time to LEARN it, is not when you need it.

For example, the first time I practiced with it I simulated an emergency at 95'. There was absolutely not enough air in the lungs to purge the water out of the mouthpiece. I was monemtarily startled but not surprised, as there is often not even enough air to equalize. You must do the math also, and be familiar with it too. The 3.0 cu. ft. size bottle holds 57 breaths at the surface (assuming 1.6 L breaths). It helps to know how your individual body uses air in contrast to the rated specs. If you know you get 57 breaths at the surface, then you know at 99', or 3 atmospheres, you will expect 57/4 (14 breaths). But you will be ascending and getting increasingly more breaths as you surface. In one drill I started ascending at 100' and finished my safety stop with a total time on the spare air of over 5 minutes.

It is imperative that you be familiar and confident with what to expect. If during an emergency you expect less performance than what you will actually get, you might be more prone to uneccesary panic. One way to look at it is, I dove down on 5L or so not expecting to use the bottle, but expecting a couple of minutes bottom time. If I were forced to use the bottle in an emergency, I take comfort in the fact that it holds 85L of air. That is the total oxygen content of 17 full inhales.

Everyday I perform 25 minutes of "single-inhale" statics on just 14 total breaths. If I were tangled and prevented from surfacing for minutes, the confidence in these numbers can make the difference of a calm enough head to correct the situation, or a panic and wasting of precious Liters. I would encourage your buddy to familiarize himself with the bottle also. You never know if you will have to hand it to him while he frees himself and you surface. He needs to be just as confident in the equipment BEFORE the need arrises. There is never a second chance to be prepared for the unexpected once it happens.

I think the spare-air is a great insurance policy, but don't grow to rely on it in place of common sense safety. And remember, once you use it, you will have elevated nitrogen levels in your blood. So figure on ceasing freediving for an hour to be sure you're more than thoroughly purged of nitrogen. I hope this answered your question, and gave you some insight to the benefits.


It has been well established that spare air bottles tend to kill you. Not because of embolism, but because you dive too deep in false security, whether you like it or not. By the time you realize you need to use the spare air, you will not be thinking clearly enough to use it. You may have already blacked out, since blackouts can happen without warning, and when you are low on air your instincts take over. Your instincts tell you to bolt for the surface. Becoming entangled on the bottom is very unlikely, and wearing a spare air for that situation will likely get you killed even though that particular situation will not happen.

If you can't dive to depth X and remain calm in all situations, then you shouldn't be diving to depth X, spare air or not.



I personally think that a spare air could be a good thing, but only under certain circumstances. Using one can however be very risky.

Using spare air is scuba diving and on top of that in an emergency situation. I think to be able to use it meaningfully you should at least be certified to dive to preferably even deeper depths than you are freediving to. Not just getting a certificate but also being a confident diver at that depth. Also you should be very good in scuba emergency training and also train with the spare air itself. Otherwise you might falsely feel safe while in the mean time the spare air adds more security problems than it resolves. Some even go as far as advising never ever to use it at all because they think the risks are too great compared to the usefullness of it.


Without scuba diving training and understanding the dynamics of breathing the compressed air at depth, chances are you WILL KILL yourself if you attempt using compressed air for emergency ascent.

Possible consecuences are:

General Barotrauma, Raptured Lungs, Atrerial Embolism. All of which might result in your death.

Please get a proper training if you plan on breathing compressed air under water.


Equipment: PowerLung

mail order suppliers of freedive equipment

Equipment: Noseclips

Paradiso nose clip

URL Paradisia



Equipment: Bi-Fins

WaterWay PowerBlades


So, New FiberBlades for SporaSub footpocket are available at last in North America.

It's a decision for openclose heel of WaterWay products.

It was a lot of discussions about that. So WaterWay LongFins are available not only in spotrs' variant but also in 'close heel'. Scuba divers can swim with them at last and join to 'fibercomunity'.

For this use PowerBlade - it's perfectly fits to SporaSub footpocket and speciaaly designed for it.

Powerblades efficiency is awesome - no comparision with carbons. The Fiberblades practically immortal - they can easy over 10000 kilometers without weariness. You cannot see serious sportsmen with carbon blades only fibers everywere: in Racing, Lifesaving, Orienting, Underwater Hokkey and Freediving. How many World records are with Fiberblades: practically all. All last records are with fiber monos Eric Fattah, Patric Misimu, Carlos...

So that's effetivity is a reason to put it on instead carbons.

It was bestseller in Europe last summer. I couldn't order even 1 pair - everything was sold before was produced,

the staff worked without weekends!

It's hardness (stiffness) types from softest to hardest.

On our site they're under Fins Tab.

They're 99 USD here and 150 EUR in Europe. Not bad price I'd say.

It's cheaper then 'native' carbon blades and much more effective.

Concerning Bi vs Monos for freediving WaterWay strongly recomends Monos for more then 30 m. In effectivity nothing can be compared with the tale. Mono is the tale. The Nature is rational.
Peter (WaterWay Canada)


Fiberplastic (sometimes they name it as fiberglass - it's old-name) is complex multy-layer polimer, usually epoxy-based reinforced by syntetic net (fiber) - elastic yarn. Thet gives it exellent elastic ability that combines from plastic elasticity and elasticity of yarn. It creates new material. Fiberplastics are composite materials. The thread makes fiberplastic elasticity practically immortal concerning material fatigue. Multy-layer construction affords create structure like whip in the longitudinal section that cerates 'rolling wave' - some sort of hydrodinamic resonance that especially strong with monos (because the big square of blade).

This whip-effect canot be done with other non-armored materials.

The professional swimmers also name this effect as a 'flick'.

Carbon in fact also plastic but on different basis, not multy-layer and without reinforcments. It has long molecular fibers but this fibers can not be compared with blatant fibers in armored plastic.

Roghly speaing it's an effort by chemical way to recreate mechanical structure. In the foreseeable future it cannot be compared with the composites.

The difference relatively plastic (Carbon plastic is the sort of plastic and nothing more) and fiberplastic power is alike between ordinary concrete and armored concrete. Something like that.

A lot depends of plastic itself. Only few countries can produce good fiberplastics - Russia, Denmark, France and Belorussia.

Russian is the best. French is good but expencive.

Sebak (Estonia) is our competitor in business and they're very good in communication with clients and have very high culture in it, hydrodinamics of their blades is quite good.

Sebaks' blades have drawback - their Belorussian plastic is not very good because desighned for other purposes and their blades often brake in the most feeble part -heel. Francly they're very nice with the clients and make the change.

WaterWay doesn't buy fiberplastic but rent the machinery and produce fiberplastic on some factory in Russia with comlete control of quality and we have our own formula of plastic. So the problem of breaking doesn't exist for us.

We can change heel-broken blades but that never happened.

So I see the good future for fiberplastics. And I belive that the best future fins will be desighned from composite materials.


the hardness has 5 tipes

it ups from 1 to 5. Now there's a new idea to measure it in kilograms (!). They are

2.5, 3, 3.5, 4, 4.5, 5 kg.

It measures so - how many kilograms we have to put in lateral direction to make deformation in 52 cm (they say that 52 is medium measure for a swimmer).

2.5 a bit is softer than LD-type of blade (Soft for bi-fins) 5 is a bit stiffer then Sprint (Hard for bi-fins).

I was trying to compare them with Scubapro native blades but failed to compare 'em - absolutely different feeling. I don't know how to compare them.

2.5 is very soft. Maybe due to softest blade it can be ideal for freediving. For spearfishing, snorkeling, scuba I'd take 3.5-4 for standart body - about 70-80 kg 175-185 cm, medium-trained swimmers or 'who lives in water' and swims very long distances.

3-3.5 are for rookies and freedivers with strong legs.


It's my personal supposition. Nobody's tryed them yet for freediving!


For advanced guys 4 and 4.5 are OK. Scuba, snorkeling, so on.

It's in fact old 'Hard' stiffness and lifesavers on competition usually select them. They're looking universal.

For high speed 4.5 (Hard) and 5 ('Extra Hard') are great. Irong-legged monsters at last have stiffness for them (5)

But I'd say thay're great but tough and demanding to swimmers shape. Speed is really high.

For women the same but (-1) in stiffness.


In fact there are 3 tipes of form of tale - arc outside, arc inside and 'fishtale' (flat about 2 cm from both sides and then goes arc inside). I think that this name gave somebody who never's seen any fish.

In reality no difference. Just a marketing. In practice they're the same. The tiny bigger performance has arc outside. But it's really tiny.

About color - nothing special. The hue of braun color just depends on color imagination of our guy who prepares the mixture for plastic.

They're absolutely same in quality just additions of pigment (salt of cromium as I remember).

Now I've on stock brown and light brown. Totally the same. If you prefer one of this colors - mail me with your order and if I have in stock color that you prefer - I'll send it. If not... well I'll send that I have then

We give discout to:

  1. National Champs
  2. Members of National Teams (USA and Canada)
  3. Professional Coaches (in fact they always buy some pool)
  4. Who buys a pool from 5 items together (and more) - and after with shipping to the same address
  5. Who has bought 10 WW items in any period of time
  6. Who has bought 3 and more fins (blades) in any period of time

ok i have worked it the plastic industry for years and lets please not call apples oranges. yes to a certain extent there is a difference between carbon fibre and fibreplastic. a spade by any other name is still a spade. the name carbonfibre blade and fibreplastic are misleading. there is something missing from the name of first, to be thorough it would be carbonfibre plastic and the other as it has been presented is a "fibreplastic". this technology is the same relatively. if we look on the name of the latter it would seem that there is something missing... what type of fibre is this in the "fibreplastic"

fibreplastic, fibreglass is the same, made of a two part composition, fibre that is layered, saturated or impregnated with resin. thus the resin would be this so called plastic in the new name "fibreplastic". yes the resin is a type of heat reactive or curing plastic that is very elastic and comes in two common compounds polyester or epoxy. the type of fibre the ammount of it, its direction and or weave makes up the flex or rigidity, the resin holds the fibres in place one reinforces the other. rienforcement brings us close to something more familiar, reinforced concrete yes you can change the concrete(resin/plastic) and you can bind it over different mediums pretesioned steel cable or rebar(carbonfibre/fibre) but it is still pretesioned concrete.

carbonfibre has its applications because of its strength to weight ratio, i.e. bicycles, airplanes, etc.

weight matters but just not as much underwater. so the fibreplastic is merely fibreglass, these industries have simply mastered the weeve, layering, substance. the product may be better and i am certain it is the reason why it is cheaper more than likely cheaper labour first and almost all fibres are cheaper than carbonfibre. why was carbonfibre first used more than likely a by-product of italian industries(bicycles namely) looking to branch out there was more than likely little thought given to other materials(fibres/resins) because of their mastery of cabon products(they are the industry leaders). so who gets the last laugh us the consumer of the current product cheaper yes, better probably, but the best is yet to come in my estimate in the form of a variety of fibres with carbon incorporated.


The name fibreglass was always a bit silly as the is no glass involved. I supposse that it was so named as the resins are transparent like glass and one could see the fibres in amongst the glass like resins. I think to call this ground breaking technology these "ibreplastic"is a bit missleading. Resins are easily modified to have different charateristics as is the fibre type and weave. The only thing new that I have noticed is the appication. I am currently working on applying yet another method from the fibre and resins industry. The problem is the company that I worked for and helped to develop this method sold the rights Ferrari 6 months ago. I will never be able to use the method comercially. Maybe I should talk to Ferrari and make a contract with them Though that would be impossible as Ferrari would demand more profits than the freedive industry permits. How would you like a pair of fins with the Ferrari name written down the length so fast and responsive just like their namesake?

A Brownsword

I bought a pair of these fibre bi-fin blades from Waterways back in September. They must have been one of the first pairs that Peter sold (in fact, I think they may have been my idea as I suggested it to Peter after trying his open heel bi-fins ). I finally got some extra footpockets and got around to mounting the blades and trying them out (only 8 months later! my apologies to Peter for being so tardy on this).

Mounting these is a bit of an issue -- I had to cut off most of the rubber stripping that comes on the edges of the blade that goes into the footpocket. To keep them together I took a drill to the blades and put 2 holes along each of the footpocket "rails", and 2 holes where the screws normally go, and then used the miracle of zip-ties to secure it.

I only spent about 10 minutes in the ocean with them today. They felt quite stable (i.e. no twisting / torque) and I think they delivered noticably more power than my plastic blades. These fibre blades are slightly longer and have a square tip with a semi-circle cut out on the end. The strangest thing about them is that they are completely flat, unlike the plastic blades, so the angle of the blades feels a little different. I'll need to use them more to get a good feeling for the differences -- perhaps some dynamics in the pool. The fibre looks like it'll be more fragile than the plastic, but that's just an intuitive impression based on the look and feel of the material compared to the plastics. I might try a friend's carbon fibre C4s as well for further comparison.


I ordered a couple of pairs of fibreblades from Peter last month. The #3 (medium hardness) arrived first and I fitted them to my girlfriend's standard sporasub foot pockets.

I just pushed the rubber edges in and glued them with black silicone glue. I had to drill two holes for the screws, but it was good that they come undrilled, so you can put them on whatever you have. The tang of the blades is slightly wide for the standard sporasub foot pockets, so they don't quite get to the back of the slit where the blade goes under the foot, but they are within 5mm of the back, so close enough. I suspect they fit pockets for Pure fins better and they woudl get more support. I will try fitting them to my Picasso fins when my blades arrive, but if they don't feel good I'll get some sporasub pockets.

As for testing, I have had a go with them and yes the blades are very very nice to use. Like carbon, they give amazing bang for your bucks. Plastic is so inferior, there is no comparison. I am not qualified to say if the fibreplastic is better or worse than carbon, but at $US99 they are better for my chequebook. They are very very nice blades and look a bit more hardy for spearfishing than carbons.

Having recently tried some sporasub variant carbons (broke those pockets in a 2 day spearfishing comp), the #3 blades are slightly stiffer. After trying the #3 blades, I felt they were a little bit soft for the serious spearo who is used to swimming all day in hard fins, but my girlfriend finds them good to use (doing -30m constant). I have therefore sent back the #2 blades I ordered for her, to swap for #4's for me. As I have strong legs and am of average to large build, I expect these will be nice and hard and challenge my legs.

I'm still waiting on the waterway mono, but am looking forward to it!


I tried a #4 pair of Waterway fiber-blades briefly this weekend. I think that they were mounted in Omer foot-pockets? They seemed dreamy to me. You could flick your way down w/ almost no effort (i.e. the blades would bend enough to provide thrust), but if you stepped on them they were stiff enough to get you going pretty fast. They also seemed to have a resonant mode if you did really fast flutters. Absolutely no twist to the blades even when you really wail on them -- the tips never touched once.

At any rate, they made my Gara 2000s look pretty sick. One of my dive-buddies tried them too -- maybe he'll post his impression.

icarus pacific

And the whole thing about fiberglass being called fiberGLASS comes from DOW being the outfit that spun the glass, as in real glass into fibers for the fledgling telecommunications industry looking for smaller conductors than the metal based wire. The fiber in the composite sandwich, be it carbon, glass, an aramid such as Kevlar, or burlap for that matter- it's all composite construction- a fiber woven with a varying warp and weft of varying weights and thickness and encapsulated in a resin matrix. no biggy.


They blades will definitely fit into OMER as I have #2 powerblades in OMER pockets. Sven is right saying that it uses the same screw and lock system. Couple of things. You will need to drill the holes for the screws in the blades yourself. Don't wory about damaging the blades because it won't. I also found that the blades would not fit into the pocket ribs unless I trimmed down one side of the rubber rails on the blade. What I did was insert the blade into the blade pocket then mark off where the ribs ended on the blade. Next I trimmed the entire top rubber rail to the marked point. This allowed the blade to fit snugly into the rib. I also found that the end of the rib would pop loose so I drilled a hole on the side of the blade next to the plastic clip and put a small zip tie there just in case.

These fins are absolutely incredible. I have gone spearfishing for over 4 hours with them and no camping or fatigue. Actually, I will get the #3 blades when I have the cash because I want a little more snap at the end of the kick. Still, these are the smoothest and most responsive fins I have ever tried. Have fun.


Well after a long wait the verdict is in. The new fiberplastic power blades from waterway absolutely rock! Okay it was an extremely long and painful wait but a couple of people came through for me and I got my footpockets. Actually I have one set on the blades and another that is supposedly in transit.

First off, I was drooling over how reactive the blades were on dry land. The would snap back instantly. I could practicaly bend the fins onto itself. There is absolutely no comparison between the Cressi HF and Waterway in so far as snap. The Cressi seemed dead as compared to the Waterway.

Installation was pretty easy. I needed to trim off part of the rubber side stabilizers on the blade to get it to fit into the ribs of the footpocket. No big deal. A sharp knife did the job nicely. I trimmed the rubber down until the end of the ribs. After drilling holes and screwing them in and getting the blades into the ribs I noticed that the clamp on the end of the ribs don't clamp too well. I chose to drill a couple of hole through the blades next to the end of the rib and use a small zip tie to keep it on snug. I did this on both sides of both fins and so far so good.

The first water test was just a simple swim. It was getting late so I drove down to a beach and jumped in with no suit; just the fins, mask and snorkel. Now I had heard that I might have to alter my kicking cylce because these blades are so reactive so after my first five kicks I thought this was going to be the case. It felt like my feet were lifting out of the water with every stroke. I decided to look at my feet while swimming forward. Hey wait a minute, my feet are still underwater. What is up with that feeling? After looking at the end of my down stroke, I noticed that these fins would flex nicely then snap back like crazy. Mucho mucho power brah! I surface swam for a wile and then did a few dynamic apneas just to see how they felt. Awesome brah! The combination of OMER footpocket and waterway blade had me smiling. Very comfortable, smooth and powerful.

The next couple of dive trips pushed me to around 50 feet max. Easy dives and the fins performed very well. I can attest to the durability as I am very tough on my gear but these fins are taking the abuse. I want to and will try these bad boys out in deep water when I get the opportunity and report back. One thing that I did notice was that despite being warned about their stiffness, I can still overpower these fins. It was suggested that I go with the #2 which I did. Don't get me wrong, these fins are crazy, I just need something a little stiffer. I will probably order a #3 when I have some extra cash.

Would I recommend these fins? Oh yeah! Seeing that they come in 5 different stiffness, there is one out there that can accomodate pretty much any diver. Those that like soft fins, stick to the #1 or 2. Guys like me who like theirs a little stiff would be better off with a #3 or 4. For those guys with tree trunk legs and elephant ankles, #4 or 5. In any case, the fiberblades rock! They are just as reactive as advertised and so far are pretty durable.


I recommend getting the full built fin with the waterway footpockets. Sure, the waterway footpocket LOOKS like crap, but it beats the crap out any 'normal' full footpocket like OMER or sporasub. Don't ask me why. Waterway bifins with waterway footpockets are the ONE to get if you like bifins. Imagine if Martin Stepanek had been using these for his WR!!


I bought Waterway bi-fins (medium stiffness) to use for underwater photography, to give to newbies to use, for safety freediving, and for fun. They rock!

I got the Waterway footpockets, not Omer or Sporasub footpockets. I am already used to monofin footpockets and it was an easy transition. Cheaper, too!

Personally, I think the advantages of waterway footpocket over 'normal' bi-fin footpocket are:

1.reduced footpocket drag

2.much better power transfer with closed toe and heel strap (requires better flutter kicking technique)


1. Foot warmth--this style of footpocket needs to be fairly snug, to make the power transfer advantages come through. (for me it's well worth the need to take the fins off every hour or so to get the circulation in my feet going again--no biggie)

The bi-fins themselves are amazing. They have a seagull action found only in monofins (which stabilizes the fin without the use of rails which deaden the fin flex characteristics), are incredibly durable, excellent power and responsiveness.

And of course, they look so retro. Everyone asks me if I made them myself!



I agree with you that the full foot version packed more punch but they beat the living daylights out of my feet. Pain man! I guess if you are doing freediving for depth where you wouldn't be in the fin for more than an hour or two it would be okay but I am a spearo who will be swimming around for 4-6 hours on an average dive. My feet couldn't take 15 minutes in the Waterway pocket. Some may say that I have a high arch in my foot but I am not so sure. I am a flatfoot and that is exactly where the bottom of the fin bit into my foot; the bottom of the arch. I thought I may get used to this but after 15 minutes I headed in and sent them back. If it works for you right on. But for me, it just didn't work.


The two footpockets are extremely different. The Waterway footpocket is an open heel; meaning instead of the footpocket looking like a shoe, it looks like a sandal. There is no heel, just a strap that goes around your heel. The design is totally different as well. The open heel waterway finpocket looks more like a bodyboarding fin; flat on the top with the pocket sort of on the bottom. The bottom of the pocket also extends about 2/3 the length of your foot and ends around the arch of your foot. Like I said earlier, it seems to pack a whole lot of punch but they tend to bite into my feet. They have a lot of power but are too painful for me to use. The OMER pocket are very stiff and provide a lot of support. I don't feel them flexing like the Cressi pocket but fit snug with a fin sock allowing no movement of my foot. It is actually a small chore to get them on and off but I don't feel my foot sliding around in the pocket resulting in a loss of power or worse yet, a loss of fin.


The problem with footpockets like OMER/SPORA is that the foot is in "walk-position"...

I don't think that the drag is a big problem but I am not shure, I would like to do some tests about this... comparing WW to for ex. OMER.

The problem with most of the traditional monopockets are that they hurts when used for more than 5min.


When a human walks the foot is flat or nearly flat.

When a human swim the feets are stretched and the area under the feets is NOT flat...

The normal monopockets allows the foot to be in "swimming position" because the heel is open but the edge where the pocket ends makes a big pressure on a very little area, that's why they hurts is my belief. This pockets are in my opinion a compromize.

In the OMER/SPORA case the feets possibility to be in "swimming position" is restricted by the pocket because it's straight like a normal shoe.


This is an ingenious tip from Sebastian Murat. If you flip the blade upside down, the stiff part of the pocket is against the top of the foot. If you extend your foot, you will see that the top of the foot is nearly colinear with the leg, so it automatically solves the "walking position" problem.

Turning a mono upside-down will alow you to glide between stroes whereas if you wear it right-side up, the biased angle will send you towards the bottom during a glide.

I was toying with the idea of modifying the foot pockets of my WW mono as follows:

  • remove the rubber pads
  • put the fin on upside down while wearing pastic "socks"
  • shoot silicone in to fill in the voids

w/ any luck, I'll end up with a custom foot-pocket. The biggest thing stopping me at this point is that my mono is perpetually on loan, since I don't really like to use it due to lack of comfort.

WaterWay Fins Ordering


Canadian retailer.


The main distributor for the WaterWay. The PowerBlades (bifins) are listed under "Spearfishing".

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