| Re: O2 slug
Interesting discussion, as everything in life you have to balance the pros/cons of the 2 alternatives.
I will try to detail my thinking about the 2 risks discussed:
RISK A: Hypoxia
possibility: extremely low , must arrive to 0,16 from the 1, 1 I usually use. I must really mess up as monitoring my PO2 is usually number priority #1
action : turn your BOV to OC (preferred for me , take 2-3 breaths from BOV and deal with the problem at the same time)or inject diluent (not so good) or inject O2 (this will have a slower response if plugged at the exhalation )
So moving the O2 to the exhalation lung will slow the response time of 1 of the 3 solutions to resolve a low PO2 situation
RISK B: Hyperoxia
Manual addition button sticking ON at great depth [ or alternatively much less risk to eject more O2 than planned by pressing the O2 addition longer (again at great depth)]
Possibility: low but out of control of diver (the manual button sticking ON)
Action: if O2 is stuck ON, remove O2 hose (or close O2 tank) and at the same time bail out or flash with diluent. Task loading will be very high as buoyancy will change fast and diver becomes buoyant
By plugging O2 to exhalation you minimize risk of Hyperoxia
risk B seems to me to be higher and because of high task loading seems worse
so by plugging the O2 to exhalation you mizimize the worst of the two risks |