Deco help.

[Dr Deco]

Dear dtdiver:

Surface Interval

There is considerable off gassing occurring at the surface. Were this not so, then there would be no need to calculate your residual nitrogen. This nitrogen is what you have in your tissues and is expelled during the surface interval.

Likewise, this nitrogen is in the tissues that can cause DCS if you fly too soon after diving. By no means is the game over after surfacing. Training agencies will tell you that, while they may be referred to as "no decompression dives," they most certainly involve decompression, i.e., off gassing.

“ The Hidden Stop”

When on the surface, the dissolved tissue nitrogen can enter into the gaseous phase if there is some strenuous physical activity. When the nitrogen enters into microbubbles, the elimination of this nitrogen is very, very slow. It has elimination time measured in hours rather than tens of minutes.

Breathing air will certainly allow the elimination of dissolved nitrogen if its partial pressure is greater than what is in the breathing air. Certainly, this is not as fast as if breathing oxygen, but there is elimination nevertheless.

The game is definitely not over. In addition, no running, climbing, jumping, etc.:boom:

Dr Deco :doctor:

 

[dtdiver]

i think that breathing air on the surface as a "hidden stop" sounds like a misconception. how can floating on the surface, breathing air, off-gassing at a rate measured in "hours instead of tens of minutes" really be called a "stop " of any kind?

yeah it will count towards your surface interval but it won't do anything towards reducing your previous dive's obligations.

doesn't your last stop have to be at a pressurized depth to keep bubbles small and gasses dissolved?
so i would think you'd be better off with extra time at 10 feet with some sort of nitrox or better.
( this doesn't include being on the surface breathing reduced n2 mixes)

i really was trying to clarify that "hidden stop" really is a might be a misnomer. there are folks who might try to use it as a way to shorten their stops or to "make up" for missed stops.
i sure won't

dt