Ascend drills - how many is too many?

[boulderjohn]

Stupid question…why would all the students have to do three ascents? I thought it was just once to prove you have the skill down pat. There doesn’t seem to be a reason for it to be done multiple times, from the exact same depth. The risk/benefit ratio doesn’t seem worth it. Unless I’m reading the post wrong.
Eta couldn’t they do skill do-overs at a shallower depth?

As I understand the post, the reason for it is to do different kinds of ascents. He mentioned alternate air ascents, for example. Why you have to do it from 25m/80 feet is something I don't understand.

 

[kaylee_ann]

As I understand the post, the reason for it is to do different kinds of ascents. He mentioned alternate air ascents, for example. Why you have to do it from 25m/80 feet is something I don't understand.

Yeah, weird, you don’t have to do the ascent from 80 feet to prove you know the skills.

 

[Jim Lapenta]

We'll soon be doing some ascend drills from 25m (80ft). Alternative air ascend, normal ascend that sort of thing. We're planning three per dive, we will not (intentionally) exceed safe ascend rate and the ascends will all be performed at the beginning of the dive. Obviously, we will be regularly asking about sinus / ear discomfort, etc. And being at the beginning of the dive there should be very limited nitrogen tissue loading. But drills being drills, there's likely going to be points for improvement, and do-overs. My question is, is there any theory or practical guidance on how many of such drills can be fitted in one training dive? Can we do 1 extra? 2? Any input / experience is greatly appreciated!

What CMAS affiliate is this? I don't see any good reason to do multiple ascents from 80ft. There is too much risk involved. If you want to do multiple ascents, do multiple dives. Unless these are tech courses there is nothing that requires this to be done from that depth.
And you don't do them at the beginning of the dive. That's stupid and risking equalization issues that don't have to happen. This sounds like yoyoing for no good reason.
All it takes is one person to have issues and the whole team is put at risk.
How many divers would be on this dive? Never mind, it doesn't matter. Everyone involved, including the instructor is taking on unnecessary risk. If the instructor has a problem and student doesn't realize it and continues to descend or ascend, they are potentially doing it alone without the instructor supervising.
Doing it just to practice the skills can be done from one atmosphere quite successfully and you still don't need to do multiple ascents on one dive. That's just asking for trouble.
If I were the student I would seriously question the judgment of any instructor who was doing this.

 

[Lorenzoid]

Stupid question…why would all the students have to do three ascents? I thought it was just once to prove you have the skill down pat. There doesn’t seem to be a reason for it to be done multiple times, from the exact same depth. The risk/benefit ratio doesn’t seem worth it. Unless I’m reading the post wrong.
Eta couldn’t they do skill do-overs at a shallower depth?

If the instructor is teaching the skill, the students might do it many times, maybe with variations in who is sharing air with whom or whatever, to ensure they really master the skill--ingrain it into so-called muscle memory. I have done hundreds of practice ascents over the course of a few years, with maybe five or six in a day, but never starting much deeper than 30 feet. I think that's the common way to practice ascents.

 

[kaylee_ann]

Doing it just to practice the skills can be done from one atmosphere quite successfully and you still don't need to do multiple ascents on one dive. That's just asking for trouble.
If I were the student I would seriously question the judgment of any instructor who was doing this.

yup that's what's confusing me too. obviously i'm just a diver not an instructor or anything but it sounds unnecessary?

 

[kaylee_ann]

If the instructor is teaching the skill, the students might do it many times, maybe with variations in who is sharing air with whom or whatever, to ensure they really master the skill--ingrain it into so-called muscle memory. I have done hundreds of practice ascents over the course of a few years, with maybe five or six in a day, but never starting much deeper than 30 feet. I think that's the common way to practice ascents.

yeah but at 80 feet? what for? waste of air too if nothing else, lol

 

[Lorenzoid]

yeah but at 80 feet? what for? waste of air too if nothing else, lol

I think that's exactly the point most of us are making. You can do the same drill from 30 feet. Sure, it sacrifices some realism ... for the sake of safety, as in other practice exercises we do.

 

[rmssetc]

I wonder if it would be better to do these practice accents from say, 18m to 6m, instead of 25m to 0, with the intention to:

1. Reduce the risks inherent in the larger relative pressure change as depth decreases
2. Get accustomed to controlling ascending to a safety stop, not directly to the surface
3. Get accustomed to the feel and actions at a safety stop (proper weight, proper amount of air in a BCD, wave motion, looking up for boats passing overhead, etc)

Of course, doing the exercise this way would be much easier if there was a "target", either a hangbar or a fixed buoy at 6m.

Certainly it will be harder to debrief after a practice ascent if students and instructor are under water, but that's what hand signs and a slate are for, right?

[You can probably tell from this post that I am not an instructor and don't even play one on the internet. ]

 

[Celt]

We'll soon be doing some ascend drills from 25m (80ft). Alternative air ascend, normal ascend that sort of thing. We're planning three per dive, we will not (intentionally) exceed safe ascend rate and the ascends will all be performed at the beginning of the dive. Obviously, we will be regularly asking about sinus / ear discomfort, etc. And being at the beginning of the dive there should be very limited nitrogen tissue loading. But drills being drills, there's likely going to be points for improvement, and do-overs. My question is, is there any theory or practical guidance on how many of such drills can be fitted in one training dive? Can we do 1 extra? 2? Any input / experience is greatly appreciated!

If you drop a nice heavy shot weight in 100 feet and run the rope through an eye in the surface buoy with a small running counter weight it will give you a nice straight line and visual reference to practice on. Once the assent and decent are controlled how many ye wish to do is up to your sinuses, doing inspections on deep moorings is a pain but I've done half a dozen at a time.

 

[Wibble]

All of those skills can be taught at much shallower depths. Ascending from 80 feet is the same as ascending from 30 feet, just more water.....and chances for problems. The risk of this doesn't justify the training value, in my opinion.

I think that's exactly the point most of us are making. You can do the same drill from 30 feet. Sure, it sacrifices some realism ... for the sake of safety, as in other practice exercises we do.

They can, but deeper ascents make it more realistic, forcing you to control your drysuit, the wing (and loop if on a rebreather). Forces you to think ahead and know how much to dump without dumping too much and descending.

Also handling a SMB at the same time.

Oh, and how can you learn what 9m/30ft a minute feels like if you're at 6m/20ft?

When you're diving -- as in doing real diving and not just in a training environment -- you need to know these things. Especially as you need to be self-sufficient when you've lost your budgies.