Freediving Good For Scuba Diving?

[Scuba_Noob]

Hi,

Is freediving good for scuba diving? Does it help make you a better scuba diver?

I'm curious about freediving. I'm wondering whether the improvements in breath holding (and decreased air consumption), as well as doing physical activity with low blood oxygen helps with scuba diving. Specifically, I guess that it might help with emergency ascents (CESA and such) and out-of-air situations. But does it also help with improving your air consumption (by requiring less oxygen)?

[g1138]

Freediving takes on the original (and now sometimes lost) fundamentals of scuba, where in the old days divers wore only enough weight to make themselves neutral at depth which would sometimes equate to buoyant on the surface.
They didn't have BC's then, so had to weight light on the surface but neutral at their depth. To get down they would perform near flawless surface dives, which is one of the things freediving teaches you.

Freediving may decrease your O2 tolerance, and it will definitely help you with your CO2 tolerance. But that alone does not change your SAC rate. A breath is a breath, no matter what you do your lung volume will not change. I like to distinguish 2 different base SAC rates. Your Sleeping SAC and your Resting SAC.
- Sleeping SAC is when you're laying on the bottom and not moving at all
- Resting SAC is more realistic for a dive, you're hovering off the bottom but otherwise not doing any other task. This is the base SAC rate most divers refer to. It is generally higher than your Sleeping SAC because you're performing a delicate task using mainly your lungs.

Your Sleeping SAC rate will always be the same because you're taking in the same amount of lung volume at every breath. Only the rate at which you take your breaths, changes your SAC rate.

Freediving can make you a more comfortable diver, which can prevent your SAC rate from getting higher due to stress. This essentially keeps your SAC rate closer to your Sleeping SAC which equates to a lower overall SAC rate during your dive.
In this sense freediving can decrease your air consumption, but it do not lower your O2 consumption. It only lowers your tolerance.

Freediving probably won't have major effects on CESA's and OOA situations though. How freedivers dive to such depth for extended periods of time is by training and keeping their heart rates extremely low. During scuba incidents you're heart rate is going to increase and you want that to be able to think and act fast. This of course increases your CO2 levels and makes you want to breathe. Lowering you heart rate will make you sluggish and honestly you don't have enough time to concentrate on that if you're OOA.


Overall I think freediving makes you a calmer more comfortable diver. It's definitely a good supplement to scuba diving in my books.

[Akimbo]

..Freediving probably won't have major effects on CESA's and OOA situations though. How freedivers dive to such depth for extended periods of time is by training and keeping their heart rates extremely low…]

I agree, from the physiological perspective of a freediver’s prep. As you alluded to earlier, freediving experience provides a level of self-confidence and psychological advantage that is perhaps more valuable.

Fear of the undergoing a new or rarely practiced experience under life threatening conditions raises anyone’s heartbeat. Being at depth with only their air in their lungs is old-hat to an experienced freediver since they have been there before many times. A freediver’s prep is as much about psychological conditioning as physiological.

From my observations, accomplished freedivers bring an unparalleled level of grace and calm to Scuba diving. I encourage anyone to become an accomplished recreational freediver before starting Scuba instruction.

g1138, nicely stated BTW

[Mark Derail]

I had fun freediving in large pools (during free swim time w/o diving boards).
Sit, lie down, make ring bubbles in the deep end.

It really helped for buoyancy control and especially equalizing.

I can now say that I am a better diver, and no longer use "extra weights" to make it easier to sink.

[Akimbo]

You might be interested in this thread: Panic in the experienced diver?

Deep in this thread I wrote the following, but there are a lot of useful insights from many Scubaboard members.

Fear, fight or flight response, or other mental activity that distracts from problem solving and corrective actions wastes valuable time in a real crisis. IMHO, one of the greatest values of experience is to minimize overreaction so an inconvenience doesn’t escalate into a perceived crisis.

The only personal crisis (excluding major physical trauma) that demands rapid, not necessarily immediate, action is oxygenation. I believe it is a primal reaction to take frenetic action at sudden lack of breathing gas, at least past the early newborn range. It probably served evolution well in that it can repel attach or get your face above water, at least for a short time.

Unfortunately, if my hypothesis is even remotely correct, this bit of evolution does not serve divers well. Most forms of crisis training are highly dependent on habituation as a key component. Habituation is not necessarily achieved in training or from experience as recreational divers know it.

My recommendation to a disciplined individual who hopes to become a great diver is:

1. Master buoyancy, not as a diver but as a swimmer: Understand that the only thing that needs to be above water during the times you are actually breathing is your mouth and maybe your nose. Any other part of the body, especially the high density skull, that is above water is a waste of energy.

2. Master swimming: You don’t have to set speed records or learn all the strokes; you are after endurance. The value here is knowing that you have plenty of time. An embarrassing number of diver drownings occur on the surface. It is incomprehensible to me how anyone can drown in a wet or drysuit at or near the surface. DUMP WEIGHT!

3. Learn basic diving physics and physiology: Pick up a book or video to learn about pressure, gas compressibility, displacement & buoyancy, and principals of oxygenation. By this time, much of it will reinforce what you have discovered in earlier steps. Don’t worry about decompression, embolism, and oxygen toxicity at this point.

4. Learn to snorkel and freedive: You can learn to snorkel from friends and gain a lot of experience. When you feel ready, pay the big bucks for a good freediving course. You will learn how to safely extend, test, and learn, your limits. Tell the instructor you want to experience hypoxic blackout under their guidance. Pool static training will give you ample opportunity. Again, the end objective is to learn you have time.

5. Buy an old used regulator and Scuba Tank: Put a paint-ball sticker on it if you have to in order to get it filled. Take the second stage apart and see how it works. Really play with it. Just don’t take it in the water yet. Try to take apart and reassemble the first stage if you are mechanically inclined.

6. Take Scuba courses through Nitrox, add rescue if you are inclined. Diving Nitrox is not the objective, gaining the in-depth understanding of diving physics, and to a lesser extent physiology is the goal. In the process, find an instructor who will guide you through free ascents starting in a swimming pool and graduating to as deep as you like. Avoid instructors who view BCs as elevators, free ascents and dangerous, and self-learning as lost income.

IMHO, this process will give most people the habituation, education, and most of the experience to make you self-reliant, confident, and capable. Individuals with the discipline and dedication to follow this path are also likely to become highly competent divers in a relatively sort number of logged dives.

This foundation will serve you well regardless of how much farther you want to go. At that point technical diving, rebreathers, or commercial diving through saturation becomes far more about mastering systems than diving.