Quote: (Originally Posted by neilh)
Not sure whether there is an easy answer to this, but here goes
Assuming several no deco dives over a number of days using 32% - is there any value in switching to a higher %o2 (e.g. 50%) for the ascent (at an appropriate depth of course)?
This came from a chat about getting some dives in with a stage/deco bottle just to get used to having one and then wondering whether there is any mileage in actually using it if its there...
Unless the dives are really long, at the depth that you would switch to 50% you are basically just increasing your deco obligation. Using O2 would help clean up the deco, but at the increased risk and hassle of carrying an O2 bottle.
If you are doing NDL (or minimum Deco) dives, then a higher O2% gas won't be helping you, and you are taking additional risk carrying the bottle.
Look at it the other way around, why are you carrying the bottle? If it is because you want to do Tech1 and want the practice carrying it, then do that, Carry it, but don't switch. How are you going to switch to it? Who taught you the procedure for switching? How are you sure you are doing it Right?
HTH
J