Ascend drills - how many is too many?

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300 spearing dives a day huh? I bet you just chill at 20 meters for a couple of minutes each dive, right?
At least, realistically I don't even come up.
Which makes my claim of 300 ascents even more dubious.
 
I have just today finished my 3 Star CMAS :).

I was with my wife so the number of ascencions is the total beteen both divers, on each drill we followed the other diver, so it was the equivalant of doing the ascencions individually.

During the week we did a total of 10 dives, 8 of which were at 36 or more, max 48m.

Day 1 : 2 dives : Max 20m(60') no ascent drills

Day 2 : Dive 1 Basic Ascension drills , 34,(112') -> 24(72')m , twice each , total 40m(120') of ascension, not including the final ascent to the surface.
Day 2 : Dive 2 - 27m(81') -> 10m(30') , once each , total 30m(90') ascencsion not including the final ascent to the surface.

Day 3 : Dive 1 38m(114') -> 5m(15') , once each ( 2 divers), total 66m(198') , not including the final ascent to the surface.
Day 3 : Dive 2 , 30m (90'), no ascension drills

Day 4 Dive 1 , 37m(111') -> 20m(60') ( 3 divers) total 50m(150') not including the final ascent to the surface.
Day 4 Dive 2, 36m(108') deep, non ascension drills

Day 5 : Dive 1 48m (144'), no ascension drills
Day 5 : Dive 2 37m (111') , no ascension drills.

At the end of days 2, 3, 4 and 5 we were very tired and went to bed early, no signs of ADD or anything unusual other than fatique.

We didn't sleep too well on these days but we believe that was due to land sickness. All of our dives involved a minimum of 2 hours of time spent on a zodiac/boat, in the beginning it was quite windy, so a little bit of rolling to be expected.

The intructors told us that their limit was around 80m(240') ascension per day, and not 90m(270') as I previosuly mentioned.

What was surprising however was the ascension speeds , we were instructed that we were allowed to do the folowing

40m to 30m up to 24m(72') per minute
30m to 20m up to 18m(54') per minute
20m to 10m up to 12m (36')per minute
10m to 5m up to 6m (18')per minute.

These were the max speeds, not necessarly the expected speeds, we never went beyond 18m(54') a minute at the lowest depths.. It differed a little bit between instructors, some of whom were ex-navy, in all cases we were expected to control and make a progressive slowing of the ascension speed as the depth decreased. Did we make some mistakes, yes, but we were quickly informed and adjusted acordingly.

At the end of the course we had become quite proficient and no longered feared the exercise.

I am not so young, 56, years old, and I am in Ok form, neither athletic nor absurdly static, my wife is a little younger and neither of us suffered anything more than heavy fatique, obviously YMMV...

We truly learned a lot about diving deep, about the mentality, the reponsability and the necessity to clearly planify and communicate in order to avoid incidents.. Nothing should be left to the imagination, incidence avoidance being the ultimate goal.

Something very important though, we were diving the mediteranean and the water was relatively warm, at the lowest 16° (60f), which meant that narcossis, cold, stress etc was not really a factor. we were wearing 7mm wetsuits,.. The same exercices in our normal lake environment, 8°(46f) at 30m(90') would probably have been very, very different .

Personally in cold waters or lakes, I would reduce the max ascension to around 60m ( 180') per day. ( Dry suits might make a difference though) but we were diving wetsuits so I am not too sure...

This was just my experience, I did not imagine that the exercices would be quite so intense, they were definately not banal ;-) On all dives the decos were respected and a safety stop of 3 minutes was also included, no dives excluded the safety stop..

In relation to the OP, "Ascend drills - how many is too many?", my first questions would be, what is the environment, the profile of the diver, recent dives, depths, experience, habits, wetsuit, physical condition etc There are very many factors that could influence the result..
 
What was surprising however was the ascension speeds
A commonly held view is that it's better to go slower the nearer you are to the surface. The flip side (that it might be OK to go faster when deeper) is discussed in another thread, but I wanted to point out that the speeds and ranges you listed result in bubble growth rates approximately the same or less than the growth rate present when ascending through 5 m at 6 m/min.

In other words, from a bubble expansion standpoint, the last one (6m/min) is the most "aggressive".

With that in mind, I wonder if the "risk" shouldn't be tied to the accumulation of a function of rate and depth (and quantity, of course). Except for Day 3, most of your ascents were somewhat deep, which I think most would characterize as lower risk.
 
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