how much OC bail-out is enough?

[Scott Sayles]

I've been reading for a very long time on the various models of rebreathers on the market. Mostly, I've focused on the CisLunar Mk-5P, Prism Topaz, Inspiration, Megalodon,CCR2000 and some homebuilts.

Question: Why aren't the divers I see (in photos) and read about in discussion groups taking more OC bail-out on dives?

I understand that very little gas is used to fill the loop, and replenish metabolized O2. What would be the procedure if you were on a deep (250+ feet), or long / shallow (say, 80 feet ) dive and accumulated 40 or 50+ minutes of deco before experiencing a worst case scenario? (catastrophic loop failure)

The on-board gas in (2) 20 cu ft cylinders seems a little iffy to rely on for this. A team bail-out protocol might be feasible, and I know it's used, but is that enough gas?

Can anyone shed some light on what's practiced ?

Cheers,

Scott

 

[padiscubapro]

If you need an answer to this you definately need further training.. ANy RB class that teaches you to do Deco diving covers this basic material.. Just because the person is an experienced OC diver doesn't mean they can do Deco required dives on a RB.. My personal bailout varies greatly.. it depends upon what surface support I have available and what divers are part of my dive team.. my Minimum bailout on dives beyond 150 ft is 40 cuft of bottom mix and 40 cuft of 50% or Oxygen depending whats available near the surface.. If I carry o2 I'll probably have to blow some of my deeper stops, do as long as I can at 20 and 10 fsw and worry about it after I get out of the water.. I also have a second stage on my onboard o2 supply (with a cutoff valve) and the air 2 type device on the lp inflator.. I have never had to bail to OC, and about the only thing that would cause me to do so is total loop failure.. Everything else I can think about has alternatives other than bailing to OC (atleast with my experience level)