UBUC

Freediving

Most of you have already practiced Freediving, although you may not know it! Every time you go underwater while holding your breath you Freedive. Other names include Snorkelling, Breath-hold Diving, and Apnea Diving. So all those times you held your breath and went under the surface to take a look at something or pick something up from the seabed, you were Freediving! The ability to move so easily and fast in the water without any heavy gear, gives you a great feeling. That's what Freediving is all about, getting the feeling that you are part of the water environment.

Freediving as a sport though, is a little more than just going under water. People often want to know how "far" they can go, to push their limits. I know, we humans are sometimes into competing. And that's good if it is done in the right spirit (remember the spirit of the ancient Olympic games when even wars stopped during the games). This is the same spirit that makes you admire the fellow athlete, not because he is better (or worse) at the sport than you are, but because he is an "Athlete" (with a capital A), and you respect his effort.

In order to compete, a few rules must be followed to allow for fair comparisons. So a few varieties or categories of Freediving are present. Constant Ballast is when you dive as deep as you can and fin your way back to the surface. The weight belt (most athletes use one) has to be brought back to the surface with you. It is called "Constant Ballast (or Constant Weights)" because whatever weights you use (to help you go down), you have to bring to the surface on your way back. Variable Ballast is when you can use a maximum of 30Kg (I think!) of weights to help you go down faster and you can leave the weights at the end of your descent before you fin your way back to the surface. Obviously people go deeper this way than in the Constant Ballast method because they don't use any energy to go down.

No Limits is when you use as much weight as you wish to assist you in the descent, and you can use an inflated balloon to bring you back to the surface. Think of this category as an "elevator" taking you deep down and then bringing you back to the surface . Dynamic Apnea is when you try to swim underwater for the maximum distance. Two variations exist, one with the use of fins and one with no fins. The above four categories are further divided into "Sea" and "Freshwater or Lake" categories. Static Apnea is when you simply get under water and hold your breath for as long as you can. All of the above categories are further divided into "Women's" and "Men's" categories.

Physiology of Freediving

This section looks at the effects of increased water pressure and breath holding on our bodies:

Ear pressure

As a Freediver (or a Scuba diver) makes his descent into the sea, the pressure on the outside of the eardrum increases and as a result the eardrum is pushed toward the inside with pain as a result. The diver uses what is known as an "ear pressure equalization" technique, to let air into the middle ear in order to "equalize" the pressure at both sides of the eardrum. A couple of techniques are available but the most common one involves closing the nose while trying to blow air through it. This "artificial" air pressure forces air to the middle ear through the "Eustachian tube".

A piece of history: In the older years, the Greek sponge divers used to "break" their ear drums when they were young by diving in deep waters without using ear pressure equalization (although they knew the technique). By doing so, they wouldn't need to equalize the pressure in their ears anymore. I know it sounds unbelievable, but it's just the truth.

Body Pressure

Imagine the following experiment. A CLOSED plastic container filled with air is slowly submerged in water. As water pressure increases around it, the container is soon or later forced to crush into itself (if the container was not closed, water would go in it and the pressures in and out of the container would be equal). Now think of our lungs as being the plastic container mentioned above.

If you are a Scuba diver, you know (or you SHOULD know :) ) that our lungs are not crushed because the air we breathe is equalizing those two pressures (the one on our lungs from the outside and the one inside our lungs). But what happens when you Freedive? Clearly there is no extra air going into our lungs to equalize the pressures. Indeed the lungs get a good squeeze. For years, Doctors used to believe that if Freedivers go deeper than a certain depth, their lungs would "crush" and death would occur. But the Freediving champions proved them wrong.

In fact those divers went well deeper than the calculations of Doctors would permit. After further experiments and observations, it was found that a "blood shift" mechanism is present in the human body. As we go deeper in water, blood starts to "shift" from other parts of our bodies and begins to flood our lungs to equalize the outside water pressure. Our heart rate slows down and blood pressure increases. This is why our lungs won't "crush" into themselves as Doctors used to believe. Interesting note: The same "blood shift" mechanism is present at all sea mammals.

Breath Holding

Holding our breath alone (even without the water pressure) makes our heart rate slow down.

Cold water

If our face gets wet with cold water (even if we don't hold our breath) our heart rate goes down as well.

Conclusion

In my opinion, based on the above scientific evidence, our bodies are designed to adapt to Freediving. The above-mentioned reflexes are also present in other marine mammals like dolphins, seals etc. We evolved from an aquatic species into what we are today. It seems that a few of our "past" abilities were not lost over the centuries.

 

Freediving Equipment

The equipment used in Freediving is very similar to that used for Scuba diving. But a few differences exist due to the different character of the two sports. When you read the following lines keep in mind that a Freediver has only ONE breath of air in his lungs and so he must use it with the highest efficiency possible.

Mask and snorkel

OK, the snorkel is not really different! But the mask is. Those of you who Scuba dive know that as you descent, you are very likely to experience "mask squeeze". So what do you do in order to prevent your eyes from "popping" out? You naturally blow a little air in the mask through your nose. A Freediver does the exact same thing.

So what is the difference you wonder? Well, the amount of air you need to blow in your mask in order to equalize the water pressure, is proportional to the volume of air that was in the mask when you started your dive. This is the reason why Freedivers use what is called a "low volume" mask. A high volume mask would need more air to be blown in it (air that comes from the lungs and not from an air tank!), and we have stated that air is a very precious thing for a Freediver.

Tip: As a Freediver ascends to the surface, the air in the mask expands. Instead of letting that air escape out of the mask (like a Scuba diver would do) the Freediver takes it back into his lungs by breathing it in through his nose.

Wetsuit

Freedivers use wetsuits that are specifically designed for Freediving. They are warm, easier to move in the water with, and very different than Scuba diving wetsuits. They are usually thinner than Scuba diving wetsuits since: a) A thinner suit allows you to use fewer weights on your weight belt (so you are more swift), b) Since you're moving more than a Scuba diver, your body produces more heat anyway, c) The thicker the wetsuit is the less hydrodynamic you are as you move in the water (so more effort is needed to swim a given distance and thus more oxygen will be used), d) The fewer weights you have on your belt, the safer you are (because during your ascent you become positively buoyant at a greater depth, so it's easier to get to the surface before something goes wrong).

Weight belt

A Freediver will soon or later go for an "elastic" weight belt. The reason for this became apparent to me when I first reached the 15-20 meter mark. As you descent, the air in your lungs contracts and as a consequence your "belly" moves in (people like me actually enjoy this, since we get to look so fit!!!). So what was at the surface a tight belt is now a pretty loose belt that might move its way down to your chest (remember your are upside down when you descent). This can be pretty annoying. A special belt is available, that remains tight as you descent because it is made out or rubber!

Freediving Fins

This is an area where the difference between Scuba diving and Freediving is quite noticeable. Freediving fins are a lot longer and stiffer than Scuba diving fins, and a lot harder to move underwater, believe me. Their main advantage is their ability to "snap" back to their original position once you get the blades to bent! You need more muscle work to make the blades bent, but the propulsion force is bigger too. It is this "snap" that gives you the needed thrust in order to move underwater most efficiently. When I first switched from ordinary fins to Freediving fins, it felt like I could "fly" underwater. One hour latter I was very tired and very mad as well. I thought I had just wasted my money. My legs were in pain for about two days. But after reading more about fins I decided to stick to them and see what happens. They are so great that now I'm even thinking of getting a pair with "carbon-fibber" blades just for deep Freediving (Does anyone want to give some financial aid? Sponsors are welcome too!!!)

Dangers of Freediving

Every sport has a few rules that should be followed. For some sports it's a mater of fair play, for others it's a mater of safety. No one gets hurt if you touch the ball with your hands in a soccer game. But you might get in serious trouble if you miss your decompression stops in Scuba diving. Freediving is one of those sports where you might get in serious trouble if you push things too far. The single biggest danger in Freediving is hypoxia. Some people call it Swallow Water Blackout. The actual blackout is a symptom of hypoxia.

Lets see how this can happen with the help of an example. Suppose a Freediver starts a dive to 15 meters in order to take a look under some rocks. As he descents the air in his lungs gets pressurized (refer to the physiology section). This causes a false sense of increased oxygen level in the lungs (increased O2 partial pressure). Now the important part: If the Freediver "pushes" himself too much and stays at 15 meters for too long, then as he ascents the decreased oxygen level (decreased O2 partial pressure) might fall below the critical value and as a result the diver suffers from hypoxia.

Hypoxia will hit you at any time your oxygen reserve drops below the critical point. In the above example, if the diver kept on going deeper and deeper, or stayed at 15 meters for a longer time, soon or later he would get hypoxia. In fact the word hypoxia is a Greek word that means that you oxygen levels have dropped below the levels necessary to sustain life. Remember that hypoxia can also hit you when Scuba diving as well, under special circumstances.

Some people call hypoxia "shallow water blackout" because most of the times it happens in shallow water, as a Freediver ascends to the surface, or even at the surface, when the freediver has already taken a breath of fresh air. A milder form of hypoxia is called "samba". This is when a Freediver makes it to the surface without blacking out but his body goes into convulsions.

The name comes from the fact that the Freediver is shaking as if he was dancing the famous dance. One thing to keep in mind is the fact that the urge to breathe is triggered an increased amount or Carbon Dioxide in our lungs. As Oxygen is used, Carbon Dioxide takes its place. Some people have observed that by practicing Hyperventilation before a dive, they are able to hold their breath for a longer time.

This is not the case. Every breathold attempt has a limit. We reach that level when the Oxygen level drops to the critical value we mentioned in the above paragraphs. By Hyperventilation a Freediver lowers his Carbon Dioxide levels so much, that he does not feel the need to breath. That is, he removes one very important warning and in effect we allows hypoxia to come into play without "knocking" the door first.

Important lesson: NEVER PRACTICE HYPERVENTILATION. In addition, avoid Freediving alone. But if you do Freedive alone, NEVER and I mean NEVER push your self. Hypoxia hits you without ANY warning. It's like falling asleep, you can't really tell when it's happening. Many people have died because they were alone when the got hypoxia. If you do want to push your self or want to do some Freediving training, make sure that you're with someone who knows what to do in an emergency situation. A person who doesn't know what to do, is no help at all. 

What to do when Freediving

Freediving is a beautiful sport. For some, it's a mind activity. For others it's a way to get fish, underwater photographs, look around and be in the water in general. Whatever you do in the sea when you Freedive, make sure it's fun. And the only way to be sure it's going to be fun, is by practicing SAFE FREEDIVING. Do not compete with others. The better you get, the more you will realize that greater depth is something that "comes" to you rather than you "conquering" the depth. If you relax and have a good time, then it doesn't really matter how deep you go. And once you stop agonizing about how deep you go, you'll start going deeper. But the nicest thing about Freediving is that is allows you to be part of a different world. Even for a brief time, you are a part of a silent, beautiful, peaceful environment.

A world that accepts you with true love, if you approach it with true love. If you approach Freediving with you mind set to "getting" things out of the sea (fish, pictures, depth records), you've lost the whole point and you won't get to the best part of it. If you go to the sea because you love her, then you will be offered her greatest gifts: moments you will never forget.

Freediving Training

For those who are interested in Freediving with more safety, finding what their limits are and who also wish to push them further, proper training is essential. By this I don't mean physical training only, but mind training as well. Sometimes mind training and physical training go hand in hand.

Training your body

Part of physical training is training in the pool. Make sure you are training with someone you knows what to do if something goes wrong. In the pool you can practice Dynamic Apnea and Static Apnea (refer to the "What is freediving" section). There are two ways to do this. One way is to hold your breathing interval constant and gradually increase your breathold time (or distance). The other way is to decrease your breathing interval while your breathold time (or distance) is held constant.

For example, suppose you are doing Dynamic Apnea. You swim underwater for 30 meters and rest for 2 minutes. Then swim 40 meters and rest for 2 minutes. Then swim 50 meters and rest for 2 minutes, and so on. When you can't go any higher, you rest for a while and start over if you can. If you do this the other way, then you swim for 30 meters and rest for 2 minutes. Then swim 30 meters and rest for 1:50 minutes. Then swim for 30 meters and rest for 1:40 minutes and so on. The same principles apply to Static Apnea Running, cycling and other aerobic exercises are very beneficial as well.

Training your mind

This part of training is in my opinion very important. Our basic target here is to be relaxed. Relaxation during a dive, helps you slow down your heart and minimize oxygen consumption. Couple of interesting things. Our brain works in four speeds or "states". Each one is associated with a certain brain wave than can be observed in an encephalogram. The "Beta" state is the state of consciousness. The "Alpha" state is an hypnotic or "trance" state when our subconscious "wakes up". The "Theta" state is when we are dreaming, and the "Delta" state is the deep sleep state.

We all go through these states at least twice a day. Once when we fall asleep at night, and once as we wake up the other day. We are more concerned with the "Alpha" state. When you are day-dreaming or when you're watching a very interesting film and times flies by, you're in a "Alpha" state. In other words, when you are so focused on something that you don't realize anything else that might be happening around you, you're in a hypnotic state.

The ability to get your self in such a state is very useful in Freediving and other sports as well. One way to practice this is to relax on your bed of couch, with your eyes closed, and focus on your breathing. Inhale with the lower part of your lungs first ("belly" breathing) and then fill the upper part ("chest" breathing). Exhale in the reverse order. As you do, imagine that with every breath you take a part of your body disappears. I start from my toes and go up, but this is a matter of personal preference. You will soon reach a point where you'll feel that you're weightless, as if your body is not there. You will be aware of the environment but you won't really care what's going on around you. Now is the time to practice static apnea on dry land. As you hold your breath, think of something different than time.

One thing I do, is focus on my heart beat. I imagine (visualize) that I'm Freediving down one meter for every two and a half (or close to that) heart beats. I leave out the finning part as it just might make my heart rate go up, and imagine that I descent and ascent with the use of will-power. The reason I count 1 for every 2.5 heart beats, is that our heart tends to follow our thinking "clock". So in a way, if you're counting very fast you might not help your heart rate go down as easily. As you get better at relaxation and visualization techniques, you'll be able to apply them together with your physical training in the pool, and your Freediving in general.

Training with our Club

Before you read the following, you should read the "freediving training" section. Clearly, Freediving cannot be done in the pool. But a good deal of training for Freediving can! So perhaps you're wondering why you should train with us instead of just going Freediving. Well,

1) By training with us, you get better at Freediving. This way, when you go out in the sea for some real Freediving you are more prepared, you won't get tired so easily and most importantly you be SAFER and have a better time in the sea.

2) If you train alone, you're putting yourself in danger. With us, there will be at least one person looking after you at all times, and you'll be looking after someone too. Believe me that the feeling of security really helps you relax during training. You'll learn what to do in case of an emergency, and that is a skill that you take with you when you Freedive in the sea.

In the beginning of the academic year, the was a person in the pool whose name I still don't know. He used to swim underwater distances with no fins, and he was alone. I asked him once if he would like to join us. His reply has "I don't consider my self a Freediver". After a few weeks, I didn't see him anymore. This person was clearly training in a similar way that we were. Perhaps he wasn't pushing himself enough to consider the whole process "training". But my point is that he was freediving without knowing it! Perhaps in the sea he would Freedive and still claim not to be a Freediver!!! Everyone has the right to do whatever he wants. But it's good to actually KNOW what you are doing. So if you want to get the most out of Freediving, you can join us and learn more about it.

Our sessions are now twice a week in term time, Tuestdays at 8:00pm and Fridays at 9:00pm. We meet at the parking lot below the Student Union building outside the Club stores (you will see all the divers there!).

---