Ascending

Question
Mike,

    Do you use any particular technique when ascending in a dry suit to help you co-ordinate venting air from the dry suit, and venting air from the BC/wing, and breathing control to achieve a smooth ascent from a deep depth, (say 100 feet),just on the edge of positive buoyancy?

                    Thank you,

                          Bill Kenny

Answer
Hi Bill,

Thanks for the question.  First, let me say that I don't have a lot of experience with dry suit diving.  My answer will be based on what I have done and there are undoubtedly experts out there who can add to what I have to say.

For me, the BC was used primarily as a surface flotation device and as a buoyancy backup in the event that my dry suit failed.  I would dive with the BC fully deflated and control my buoyancy strictly with the dry suit.  That way, I only had one air volume to adjust.  With precise air inflation control as my depth varied, I was able to control most of my diving with lung volume.  When it was time to ascend then I could control the entire ascent by bleeding air from the dry suit.  I was careful to control the venting of the dry suit so I didn't come up too fast.  If the ascent rate gets away from you then you may have to over vent and then re-inflate to re-establish control.  with practice, I was able to make slow controlled ascents and stayed right on the edge of positive buoyancy.

I'm assuming that you are not over weighted for your dives.  If you are, then buoyancy control becomes much more difficult since you're dealing with a larger volume of air and buoyancy will change markedly as your depth changes.  Good buoyancy control under those circumstances would be exceedingly difficult.

Bill, I hope this helps you and, once again, my dry suit experience is limited so I can't really throw any nifty tricks at you!!

Dive Safe!!

Mike Giles
Mike's Dive Center
mikescuba.com