I would eliminate as many failure points as practical in my breathing gas supply:
All of my breathing gas would be in a single tank with one first stage, one second stage, one SPG, one lp wing inflation hose and one suit inflation hose (if diving dry.)
I wouldn't split the gas I was carrying up into multiple bottles with mutliple 0-rings, second stages, hoses and spgs to fail. In other words... no ponys, doubles, spare airs.
I would split the gas up through planning and set aside enough gas to make a controlled ascent from what ever depth/time I was at in the event of a failure in any component. This amount of set-aside gas would change during the dive as the depth/time evolved.
All of my breathing gas would be in a single tank with one first stage, one second stage, one SPG, one lp wing inflation hose and one suit inflation hose (if diving dry.)
I wouldn't split the gas I was carrying up into multiple bottles with mutliple 0-rings, second stages, hoses and spgs to fail. In other words... no ponys, doubles, spare airs.
I would split the gas up through planning and set aside enough gas to make a controlled ascent from what ever depth/time I was at in the event of a failure in any component. This amount of set-aside gas would change during the dive as the depth/time evolved.