If the ascents are well controlled and slow, you can do a number of them without harm. I can't even keep track of how many ascents from 14 feet I do during a pool session! But I did have a rather nasty experience as a newer diver, where we were practicing skills while ascending at night, and we lost control of a couple of ascents and corked from ten or fifteen feet. I think we did something like seven ascents from the 20 - 25 foot range that night, and were never any deeper. Driving home, I felt as though I were back in residency, and trying to drive after having been up 72 hours straight. I fell asleep at a stop sign and my foot slid off the gas pedal . . . and this was at about 8 pm, the day after a good night's sleep. I firmly believe that subclinical DCS is real, and that I had it, and it wasn't fun.
Edited to add that I see nothing wrong at all with surfacing to debrief skills. I would combine several into a given immersion, but you can't realistically debrief things like, "I'd rather have you more at my depth and up on my shoulder; you got a bit behind and above me, and I couldn't see you," very well on wetnotes.
Edited to add that I see nothing wrong at all with surfacing to debrief skills. I would combine several into a given immersion, but you can't realistically debrief things like, "I'd rather have you more at my depth and up on my shoulder; you got a bit behind and above me, and I couldn't see you," very well on wetnotes.
