Question How to practice deco ascents?

[happy-diver]

Remember that perishable skills are perishable - diving every couple weeks probably isn't going to get you enough practice to really master skills, as you will see skill atrophy after a few days of not diving. There are things you can do to regularly visualize the skills and procedures, but that isn't going to help any of the muscle memory.

Mate, do you ring someone to turn the taps on, if you haven't had a shower for a couple of days

A few days, can you actually dive, mate whoever brainwashed you should join a stop wars council

 

[steinbil]

Remember that perishable skills are perishable - diving every couple weeks probably isn't going to get you enough practice to really master skills, as you will see skill atrophy after a few days of not diving. There are things you can do to regularly visualize the skills and procedures, but that isn't going to help any of the muscle memory.

I'm acutely aware of the drawbacks of less frequent diving, which is also the reason for this thread to try to mitigate it somewhat. Since becoming a father 3 weeks ago, my schedule is not so flexible.

Actually the inability to easily practice efficiently and with multiple repetitions on any given skill has been my biggest frustration in Scuba. Being a musician and a dancer, I'm used to hours of highly structured and focused practice on a daily basis.

What am I doing to cope? I do swim training in the pool 3-4 times per week for physical exercise and to increase comfort in the water, and I also simulate underwater drills while breath holding (I'm not able/allowed to use scuba gear in this pool). I'm also now looking for ways to maximize the training output of some dives, hence this thread...

 

[Lorenzoid]

Actually the inability to easily practice efficiently and with multiple repetitions on any given skill has been my biggest frustration in Scuba. Being a musician and a dancer, I'm used to hours of highly structured and focused practice on a daily basis.

My dive buddy, who is also my wife, is a musician and teaches that subject at university. I understand the drive to practice with multiple repetitions. Do the best you can with the shallow ascent repetitions. It certainly helped me. That combined with simply trying our best to do a good minimum deco ascent on every "real" dive is probably all we can do to prepare.

 

[Marie13]

I'm acutely aware of the drawbacks of less frequent diving, which is also the reason for this thread to try to mitigate it somewhat. Since becoming a father 3 weeks ago, my schedule is not so flexible.

Actually the inability to easily practice efficiently and with multiple repetitions on any given skill has been my biggest frustration in Scuba. Being a musician and a dancer, I'm used to hours of highly structured and focused practice on a daily basis.

What am I doing to cope? I do swim training in the pool 3-4 times per week for physical exercise and to increase comfort in the water, and I also simulate underwater drills while breath holding (I'm not able/allowed to use scuba gear in this pool). I'm also now looking for ways to maximize the training output of some dives, hence this thread...

Check with dive shops in your area. Perhaps they might let you piggyback on a pool session so you can get some uw time

 

[steinbil]

I repeated the ascents at least five or six times, sometimes a dozen times, over the course of two or three hours (or until my buddy and I got cold or bored out of our minds)

So I guess multiple repeated ascents from let's say 12m is OK, as long as the ears are doing ok and there hasn't been a lot of nitrogen loading first (I would think repeated ascents at the end of a longer dive would be more risky, no?). In my Fundies class we did 3-4 shallow ascents in one dive, but stopped a few of them at 3m instead of going to the surface.

What about practicing the lower part of a deeper ascent? I have much less practice doing the 9m/min speed. Many dives get increasingly shallower before starting the ascent, and I have a suspicion that some of my deeper ascents have been too slow. How can I gain confidence ascending more quickly and still hitting the first stop accurately, when I experience it so infrequently?

Would repeated ascents from 21m to 12m be reasonably safe? Would it be safer to repeat 30m to 21m because of the lower difference in pressure? Or do I have to accept only being able to practice the 9m/min once per dive?

 

[JoeTPhilly]

Like Lorenzoid said during fundamentals the instructor had me do ascents from shallow depths and then repeat. On subsequent ascents with more complexity (sharing air, sharing air and shooting DSMB). I would think scheduling a day to just practice multiple ascents in shallow water would be good. The problem I have run into is finding other GUE divers to practice as GUE doesn't have a large community outside of a few areas in the USA.

 

[Nick_Radov]

So I guess multiple repeated ascents from let's say 12m is OK, as long as the ears are doing ok and there hasn't been a lot of nitrogen loading first (I would think repeated ascents at the end of a longer dive would be more risky, no?).

Yes. The issue isn't with nitrogen loading per se, but with bubbles. On any deep-ish dive you're likely to get at least some venous inert gas bubbles even if you do the correct deco.

Venous and Arterial Bubbles at Rest after No-Decompression... : Medicine & Science in Sports & Exercise

eliminated as they pass through the lungs, although their occasional presence in systemic circulation (arterialization) has been reported and it was assumed to be the main cause of the decompression sickness. The aims of the present study were to assess the appearance of VGE after air dives...

journals.lww.com

Normally those little bubbles will be trapped in your lungs and resolve without causing any problems. But if you descend again then those bubbles can be compressed to a small enough diameter to squeeze through the capillaries. Then when you ascend again those bubbles expand on the arterial side, potentially causing ischemia and type-2 DCS. So, at the end of a longer dive don't ever descend again without first completing a proper surface interval (unless it's an emergency like you have to rescue someone).

In my Fundies class we did 3-4 shallow ascents in one dive, but stopped a few of them at 3m instead of going to the surface.

The relative pressure change is greatest near the surface so bouncing up and down from 3m to the surface can be rough on your ears.

 

[Nick_Radov]

FWIW, I never practiced deco ascents per se. When I began deco diving, I simply did deco dives, but I remained very close to the anchor/mooring line during ascent--just in case I would need to grab it.

In an emergency you might have to start the ascent from wherever you happen to be and won't necessarily be able to return to the anchor / mooring line. For ocean diving in places like California or Florida the strong currents can make it unsafe to use a fixed anchor / mooring line at all so it's better to practice ascent drills with an SMB in shallow water within the NDL. Need to be comfortable with doing a drifting ascent without having a fixed line.

 

[rjack321]

So I guess multiple repeated ascents from let's say 12m is OK, as long as the ears are doing ok and there hasn't been a lot of nitrogen loading first (I would think repeated ascents at the end of a longer dive would be more risky, no?). In my Fundies class we did 3-4 shallow ascents in one dive, but stopped a few of them at 3m instead of going to the surface.

This is the most common and useful way to practice.
1) the N2 loading is basically nothing
2) you are practicing where pressure changes are more acute
3) you are saving your ears a bit by not going all the way to the surface

If your 9-6-3m stops are solid the deeper ones are really no big deal and don't require any specific practice per se.

 

[rx7diver]

In an emergency you might have to start the ascent from wherever you happen to be and won't necessarily be able to return to the anchor / mooring line.

Agree, 100%. Like many others here, I, too, have ascended from a deco dive under a DSMB IRL. My post (to which you are responding) was referring to when I began deco diving. (When I began deco diving, I never practiced deco ascents per se.)

rx7diver