Question How to practice deco ascents?

[steinbil]

Not sure if this belongs in the technical or advanced scuba forum, as it concerns practicing to prepare for technical dive training...

Any ideas for practicing deco ascents in an efficient manner? It is a little frustrating to only be able to do one ascent per dive, especially in periods where I can't dive regularily. How can I get some repetition in training for ascent speeds and hitting/holding stops on a single dive?

Would it be more beneficial/safer to simulate ascents at depth where pressure changes are smaller - let's say stopping every 3 meters from 21m to 12m and descending to repeat? Or is it better to just do repeated shallow ascents in the beginning of a dive (before significant nitrogen loading) from 12m to 3m?

I also need to practice the different ascent speeds, 9m/min (which I guess needs to happen at depth) as well as 3m/min (could technically happen at any depth, but closer to the surface is more realistic and more challenging...).

Or is it better to just do repeated single stop ascents, let's say 9m-6m-9m-6m-9m etc. ?

For context:
I'm a GUE recreational diver preparing for GUE tech classes, so I'm practicing min-deco ascents (9m/min to half depth, then 3m/min as 30 second stops at each 3m interval).

PS.
I understand the concerns about doing several full ascents from depth in one dive (as mentioned in this thread), which is why I'm trying to find other ways to simulate ascents to be able to get more repetitions while practicing ascents.

Edit to add:
I don't know if it's frowned upon to tag people for answers here, so please excuse me if it is, but I would love to hear what the GUE technical instructors would have to say about this, like @johnkendall, @mer, @kierentec, @AnnikaPersson (Hei Annika!). Feel free to tag others (as long as it's an accepted practice...). Of course I would also like to hear the advice of tech instructors from other agencies (@tbone1004, @boulderjohn are names I keep seeing on here), as well as other experienced divers.

 

[Minion_Diver]

When I am practicing deco ascents I create a deco schedule based on a dive I want to do and follow it with focus on holding the shallow stops without variation in my depth. I do not go into deco if I am practicing deco ascents, just in case something were to go pear shaped you are not actually bound by a deco obligation.

 

[Compressor]

Interesting questions @steinbil. Should get nice commentary.

 

[Jack Hammer]

A good start is to get comfortable and stable with your min deco ascents at 9m, 6m, 3m. There is more bouyancy shift at those that at the deeper ones. Being able to easily hold these without struggling will help quite a bit overall when you take tech classes.

 

[happy-diver]

Buzz around at safety stops, I get that from the bugs and frogs on the surface of ponds
but you do it at 5m, and 3m, and 1m, when you can do it there, you can do it anywhere

 

[Lorenzoid]

Would it be more beneficial/safer to simulate ascents at depth where pressure changes are smaller - let's say stopping every 3 meters from 21m to 12m and descending to repeat?
. . .
For context:
I'm a GUE recreational diver preparing for GUE tech classes, so I'm practicing min-deco ascents (9m/min to half depth, then 3m/min as 30 second stops at each 3m interval).

This is exactly what I practiced in preparation for the Fundies tech upgrade evaluation, though I started shallower, at about 12m (40 feet) and stopped every 3m (10 feet) up to the surface. Whether doing this from deeper is safe or has such additional benefits that it is worth increased risk has been discussed before, and I believe the majority advised against it. You may be able to find that thread.

Also, further to what @Jack Hammer said, once I had practiced ascents enough to simply be able to stop and stay still, I added task loading at each stop. My buddy and I would play a game of attaching and removing a clip to the line at each stop, but there are all kinds of things you could do to add task loading.

 

[steinbil]

Thanks for the suggestions, but what about repeated ascents? If I can only dive once every two weeks or so, it doesn't feel like there's a lot of progress...

 

[rx7diver]

... Any ideas for practicing deco ascents in an efficient manner? It is a little frustrating to only be able to do one ascent per dive, especially in periods where I can't dive regularily. How can I get some repetition in training for ascent speeds and hitting/holding stops on a single dive? ...

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.

I made my first deco dives wearing a drysuit (Great Lakes), and I kept a minimum amount of air in the suit until I reached the shallow, longer stops, where I would want a bit more air in the suit (to loft the undergarments), especially during the 20 ffw, oxygen stop. Having a larger bubble in the suit when shallow meant I needed to be extremely diligent.

rx7diver

 

[Lorenzoid]

Thanks for the suggestions, but what about repeated ascents? If I can only dive once every two weeks or so, it doesn't feel like there's a lot of progress...

Further to my reply above, 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). We did this at a lake, about once every 3 weeks. I'm still not very good at it. After a number of months of this practice routine, I became good enough for the tech pass, but if I were going to sign up for Tech 1 (which I have not yet done--I went the cave route instead) I would want to practice a lot more.

 

[ntlhui]

...

Any ideas for practicing deco ascents in an efficient manner? It is a little frustrating to only be able to do one ascent per dive, especially in periods where I can't dive regularily. How can I get some repetition in training for ascent speeds and hitting/holding stops on a single dive?

...

I also need to practice the different ascent speeds, 9m/min (which I guess needs to happen at depth) as well as 3m/min (could technically happen at any depth, but closer to the surface is more realistic and more challenging...).

...

For context:
I'm a GUE recreational diver preparing for GUE tech classes, so I'm practicing min-deco ascents (9m/min to half depth, then 3m/min as 30 second stops at each 3m interval).

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.

The GUE min deco ascent is already practice for how to prepare for future deco stops, since you are already doing the 9m/min ascent to 50% of depth, then 3m/min ascent at 3m/1 minute stops to the surface.

Here, the key is to not give yourself room to be lazy - given a starting depth, you can compute what the nominal timeline ought to be. Write this down on a slate referenced to the start of your ascent, such that you know that at x minutes after the start of your ascent, you should be at y depth. This is the standard to which you have been trained and are expected to perform to.

Use some timing device (maybe your DC has a stopwatch, or maybe you simply wait to the top of the minute to start your ascent), and see how well you are able to stick to that profile. Your DC should even be able to tell you after the fact how well you held certain rates and stops. Using an SMB on the 1 minute stops gives you real-time feedback on how well you are holding the 1 minute stops.

If you want to extend stops to work buoyancy skills, keep in mind that extending these stops means extending your minimum gas requirement, but if you plan to do 2 or 3 minute stops, you should be able to plan the gas requirement to do that entire ascent (including the part where if you do have an OOG event along the ascent, what the min gas requirement is at that point. Hint: what you've done is reduce the average ascent speed from 2m/min to 2 or 1 m/min...)

I suppose if you wanted to just train these, you could do a bunch of sawtooth profiles, but your ears, buddy, and DC might not be too happy with you afterwards. The key thing here is to not simply accept your current performance, but to be critical and really dig into what actually happened, why those happened, and be able to make yourself a plan for future dives. I.e. don't just dive and think "oh well, today was just a bad day, I'll do better next time".