Exhale Diving for the "average" diver

[laminar]

Perhaps they were diving with an "inhale style" - moving around a lot, tense, wasting energy, etc...

Diving FRC is something to approach carefully and over a long period of time. It requires a whole new mentality. Perhaps it is not a good thing to add on at the end of a course with inhale dives (and packing?).

[Fondueset]

Speaking of air. I've been doing a lot of shallow dives lately - as is normal around here - particularly in summer - because the deep water is out there with the boats. Anyway - these have been around a breakwall (the one with the suckers, Cdavis) - which is just busting out with life right now. Because the dives are mostly <8 meters I've been adjusting ballast with breath - diving quite a bit on half a lungful or less. I'm beginning to understand the comfort factor with this type of diving - I think it is in some measure due to the overall neurological configuration affected by exhalation. I can see a natural evolution toward more of this type of diving but, for my part, I think I'll approach it in a spirit of quantum insurgency.

[Tommy_R]

Hmm
they where just hanging on the rope and not moving around.
I didn't want to scare you connor i just wanted to explain why i am a lot more careful with that kind of technique.
To be honest i can't remember all their performances but they all where in good shape ( one of them did a 6min static after 4 day course .... grrr ... i still can't do that )
I didn't check their breathup but they did about the same as for inhale dives, and for all of them where very very ambitious they tended to over-( hyper) ventilate.
So i just think that ( slight hyperventilation) combined with exitement and compression which triggered enough dive response, got them over their limits.
As mentioned they really didn't move at all exept the hangling down and up the rope .... but they stayed really long ( and i think most of them where closer to empty lung than frc .... ambitious.. )
i still think it's not too scary ... they exaggerated a bit and learned their lesson ( and so did I, by doing the safety )
For me that just points out what laminar said in all the other posts: You have to improve slow and try not to push yourself to fast.
They just didn't know how their body reacts on a empty lung dive .... give yourself enough time to learn that and there shouldn't be a problem at all.


Tommy

@ laminar : there was no packing , and it was no real " frc" divestyle lesson they just should feel the compression once.
usually they did 2 exahle dives in a course ... as a warmup for their final " deep " dive ( most of the time 20-28m).

[cdavis]

Tommy, thanks very much for the detailed report. I'd been wanting to get some info on exhale dive B0s.

Sounds like lowering your ventilation level is more important than I realized. I tried a lower level of ventilation in the pool today, did not cut my dive times to any significant degree. Feels kind of strange (and uncomfortable at first), going down with a higher level of co2 than normal, but I guess the body just adapts.

Connor

[laminar]

Originally Posted by cdavis

Tommy, thanks very much for the detailed report. I'd been wanting to get some info on exhale dive B0s.

Sounds like lowering your ventilation level is more important than I realized. I tried a lower level of ventilation in the pool today, did not cut my dive times to any significant degree. Feels kind of strange (and uncomfortable at first), going down with a higher level of co2 than normal, but I guess the body just adapts.

Connor

This style of diving is so much counter to where freediving has gone before this. Simple and effective. No "breathing up" and no effort to get down. And both are absolutely critical.

[Haydn]

Since my heart problems and no breathholding or diving at the docs orders for the last three years. But now with my heart fixed and medicals signed, I feel like a beginner freediver. Everything feels strange, just like it did at the start. My static is now only 3 minutes (but I know it will return with training). My limiting factor apart from low statics (PB 4:20), was always equalising, I always had to turn through failing an equalise, never because of running out of O2. In order to equalise I would pack, I needed the air to equalise to -57m. Without packing I would fail much sooner and now this thread says dont pack and even dont take a lungful with you. I find it hard to believe.

Despite that, my theory is that with my current low static, I probably wont have sufficient underwater time (for a season) to get deep enough for equalising to become the limiting factor. One day I will get deep again, so I might as well try to learn FRC as this should provide more equalisation training as I spend time above 30m getting used to being under water again.

However, the problem I see, is lack of bouyancy. It was always a comfort to me on the ascent, that I could pass through 30m and then relax, ultimately reaching the surface. Now I will have to expend much more effort swimming all the way to the surface, just at the time when O2 is dropping off rapidly through the lower intake of O2 at the start and greater effort at the end. I am not convinced and still in the old mindsight of three years ago.

I do like the idea of gliding right from the start though, and therefore having nothing else to do, but learn to equalise on less air volume. Hopefully , once trained again, I will have the equalising technique sorted and with a mended heart that beats properly now, I might even be in better condition than before.

[cdavis]

Update.

I've continued pool practice with all too infrequent real diving and improvement has been pretty amazing. In real depth, I'm down to 80+ and that was a while back. My guess is 90 ft will be ok the next time I get out.

In the pool has been incredible. I think the last time I posted a number, my practice dive PB was 2:15 or thereabouts, a hard dive. Now, I'm regularly doing over 2:40. If I stop at 2:30, I have very little urge to breath. Today I did a 2:55 that included a 2 minute static and a 50 yard swim. It wasn't all that hard and on an day I was a little off. No doubt I can go way past 3 minutes. No way in Gods green earth I could do that full lung. About 3 weeks back something really started to work and my times began to increase dramatically. Not sure how long this phase will last, but it sure has been fun.

I think (speculate) that there are three things working together that are allowing this. 1. Long term adaptation to FRC conditions so that my reflex is kicking in stronger and earlier. 2. Screwy minimal breathup using diaphrymic breathing only(roughly 1/2 breaths) and pausing about 3 seconds before and after each breath. 3. Doing it a lot, 3 days a week for the last 9 months. I'm also doing a couple of short reverse pack negatives before each practice dive in a attempt to deepen my dive reflex.

The "breath up" I'm using is bonkers to me, but it seems to be working fabulous. Laminar has been recommending the concept for a while and I just could not quite believe it would work for me. I tried his "submaximal" breathing idea as a way to take more co2 down with me, and shorten my dives on days I had no buddy. Did not work. After a couple of weeks acclimation, my times took off. More co2 or not, I can stay down much much longer and more comfortably. Maybe it is the greater level of relaxation, or less effort spent breathing or lower heart rate. I don't know, it just works. Anybody care to speculate on why?


Whats everybody else doing?

Connor

[jay cluskey]

at what depths do you start encountering narcosis

[Mullins]

The shallowest I've been narked is at just over 60m, but that was a recent VW spearfishing dive and I only noticed it after 20-30 seconds on the bottom. On normal CW dives narcosis is noticeable past about 80m for me, then gets really strong on the way up (producing CO2). I expect you'd get less narked on FRC dives because you don't produce as much CO2.

I guess Eric is the only diver who's been deep enough on FRC to experience narcosis. Well, him and Seb. Murat.

[cdavis]

A tricky question with a subtle answer.

You encounter narcosis from the surface down. The deeper you go, the worse it gets. It gets incapacitating somewhere south of 300 ft, but can be seen in intelligence an coordination tests given divers at much shallower depths, like 100ft or less. Maybe someone with more data or a better memory can give better numbers. I, and several other FRC divers, have reported feeling much more clear-headed at depths of 90 ft and deeper. That clear-headedness is attibuted to the lesser effects of narcosis resulting from diving with less than a lungfull of air(a lot less nitrogen).

Connor

[Mullins]

Why would having less nitrogen in your lungs reduce the amount present in your blood? I mean, the amount dissolved is presumably not limited by the amount available in your lungs otherwise you'd lose most of your lung volume over the course of a dive.

[Fondueset]

Mutants.

Now I feel all pathetic. I got nobody to spot me so I've just been doing limp little 50 meter monofin sprints 3 or 4 times a week - plus a couple 2-3 hour dives on the weekends.. I can't even find water thats 90 feet deep.

[cdavis]

Mullins, Better somebody more technically oriented than me should answer, but roughly, when you dive full lung or pack,versas 1/2 lung, there is much more nitrogen available in the lung to diffuse into the bloodstream. More nitrogen into the bloodstream = more narcosis. At least that is the theory as I understand it. Maybe also, lower lung volume means less surface area for gas to diffuse across.

I've also wondered if this is the correct explanation for being more clear headed at depth when diving exhale. It sounds good, but I wondered. Whatever, it is one of the nicest things about depth and exhale diving. Note: my "deep" and your "deep" are entirely different numbers.

Fondueset, have I got a solution for you. Check your pms by tomorrow.

Connor

[azapa]

Originally Posted by cdavis

Update.

Today I did a 2:55 that included a 2 minute static and a 50 yard swim. It wasn't all that hard and on an day I was a little off.

Connor

Connor, let me get this straight: you swim 50M DYN (in a pool I guess) with a monofin(?), and hang about 2 mins thereafter in static? Again, this is with about 50% full inhale, and the "submaximal breathing"? At what point are contractions starting?

Would you describe yourself as a "do good in pools" person in general or "better deep"?

Looks like something quite cool is happening to you..

[cdavis]

Weird isn't it, and very very cool.

In exhale style diving, you try to make the first part of the dive a near a static as possible, allowing time for the dive reflex to set in real strong. Then start swimming. I'm diving at about .6 if a full exhale (thats dropping slowly) Also using stiff, plastic bifins, not nearly the best for this kind of thing.

Exhale (FRC) theory says static till the first urge to breath then you should be able to swim an equivalent amount of time. Recently, I've had no buddy on many days and have been pushing the static portion a little and cutting way back on the swim portion, coming up well before a strong need to breath. Times kept going up as the static portion got longer and last week I was shocked to see 2:34 on the clock when I came up. Its just gotten better from there.

Better in pool or ocean? Well, I'd sure rather be real diving. Pool stuff is strictly to keep myself in shape for the real event. I don't get as good a times in real diving because the conditions aren't nearly as controlable, but better pool performance always leads to better real diving. If I had to go out on a limb, I'd guess that I'll be doing a little over 2 minute dives next time I get to try it.

Connor

Normally, once I get in the groove, I start getting contractions about !:30, but that varies quite a bit.