Ascent rate below off gassing ceiling?

[cathal]

Cathal, am I understanding correctly that you're ascending as rapidly as possible from a depth of 90 meters to a shallow first decompression stop?

Best regards,
DDM

Regarding the term 'rapidly as possible' - I am in control of the ascent but I am ascending as fast as I can manage to the first stop on any deco dive. From the first stop onwards its back to normal ascent rates between stops.
For me the advantages of ascending fast is the on-gassing perspective but also from a bail-out perspective. Your getting shallow where your O.C bailout lasts longer.

Finally, following Dr Doolette's advice I usually add an additional 10-15 mins between 6 - 3M on O2 as a precautionary measure.

 

[CephBirk]

?? 9mps is about 30fps. 9 meters per second is *very* rapid ascent. I think 9mpm is what the op meant.

Oops! Yes, definitely a typo! Thanks for the thoughtful responses all.

 

[Duke Dive Medicine]

True, but I know it is done by some 'record dives'. (world record I don't know). I don't have problems with deep diving. But it must have a reason like a nice wreck, a nice wall, a nice cave.
From my own personal experience, the problems start around 130m depth. 1 time I had some hpns, on another dive I felt relaxed but was breathing 14-16 times a minute (normally 6-8 times), so it was time to leave that depth, and around 110m I was breathing normally again. But the best dives are cave dives in shallow caves with warm water. Deco is boring too

Wow, so you're well beyond established limits even for surface-supplied bounce diving. You're kind of your own experiment at that point. I'll wish you wisdom and safety, and I would be interested in hearing more details about your experiences

Best regards,
DDM

 

[Duke Dive Medicine]

Regarding the term 'rapidly as possible' - I am in control of the ascent but I am ascending as fast as I can manage to the first stop on any deco dive. From the first stop onwards its back to normal ascent rates between stops.
For me the advantages of ascending fast is the on-gassing perspective but also from a bail-out perspective. Your getting shallow where your O.C bailout lasts longer.

Finally, following Dr Doolette's advice I usually add an additional 10-15 mins between 6 - 3M on O2 as a precautionary measure.

Thanks. I wonder if we have different definitions of the word "fast". An extremely fast ascent to a shallow depth in order to get out of on-gasing territory is something of a blunt instrument without precise measurements of dissolved inert gas levels and knowledge of individual tissue supersaturation tolerance at that particular time (impossible to know real-time with current technology).

The additional 10-15 minutes on O2 is interesting. Another SB member and I were PMing back and forth about this as a form of "aggressive DCS avoidance" or whatever you'd like to call it.... an added safety factor to decrease the probability of DCS, especially if you're diving in a remote area.

Best regards,
DDM

 

[cathal]

Thanks. I wonder if we have different definitions of the word "fast". An extremely fast ascent to a shallow depth in order to get out of on-gasing territory is something of a blunt instrument without precise measurements of dissolved inert gas levels and knowledge of individual tissue supersaturation tolerance at that particular time (impossible to know real-time with current technology).

Your welcome, my point exactly, as an amateur tech diver, I can only give you a non-scientific empirical interpretation of what I consider fast in comparison to a normal ascent.

Best regards

Cathal

 

[Germie]

Wow, so you're well beyond established limits even for surface-supplied bounce diving. You're kind of your own experiment at that point. I'll wish you wisdom and safety, and I would be interested in hearing more details about your experiences

Best regards,
DDM

No, it was not me. I dive outside of certification limits, but I do not like bounces, dives must be have something to see.