DevonDiver
N/A
For light-moderate tech dives that only require a single deco gas (50%), I'll generally carry a large surplus - an AL80, rather than an AL40. For me, that has logistical benefits. The additional benefit is that there's no question that I couldn't support a buddies' deco.
Obviously, for teams of 3.... 3rds reserve from 2 divers provides enough total gas for 1 diver.
For dives with shallow stops sufficient to warrant two deco gasses (50% & 100%), there are new options. It depends which of the gasses was lost. If it's a reg failure, the first choice is feather breathing or reg swapping....self-sufficiency. "Lost" gas really only means a valve or tank o-ring failure... or you failed to recover the cylinder after staging.
If one diver failed to recover cylinders, then both divers probably would have... so the issue of sharing becomes void.
If the deep deco gas (50%) is lost the options are for the OOG diver to complete those stops entirely on backgas or to share 50% with them. That's down to the dive parameters and gas carried. Another good reason to carry more 50% than calculated.
If the shallow deco gas (100%)is lost there are more options. The OOG diver can now deco on your surplus 50% rather than backgas. Another validation for carrying larger 50% volume. Your O2 deco expires first, so they switch to your reserve of 100%.
In respect to switching algorithms; I don't see by difference between choosing to pound the m-value or just opting to skip planned deco.
The only feasible time to adjust the algorithm more aggressive is if you've opted for a very over-conservative setting in the first place. I do that sometimes because I'm considering post-dive factors...and/or I'm on dives where I'm not in any rush to exit the water. I'm a fan of surfacing as clean as I can. For instance, swapping from GF70 to GF85. Post-dive factors can be dealt with post-dive.
But as it's been said... knocking off some conservatism isnt gonna solve any problems for lost gas.... the deco time savings will generally be irrelevant to the big picture.
Obviously, for teams of 3.... 3rds reserve from 2 divers provides enough total gas for 1 diver.
For dives with shallow stops sufficient to warrant two deco gasses (50% & 100%), there are new options. It depends which of the gasses was lost. If it's a reg failure, the first choice is feather breathing or reg swapping....self-sufficiency. "Lost" gas really only means a valve or tank o-ring failure... or you failed to recover the cylinder after staging.
If one diver failed to recover cylinders, then both divers probably would have... so the issue of sharing becomes void.
If the deep deco gas (50%) is lost the options are for the OOG diver to complete those stops entirely on backgas or to share 50% with them. That's down to the dive parameters and gas carried. Another good reason to carry more 50% than calculated.
If the shallow deco gas (100%)is lost there are more options. The OOG diver can now deco on your surplus 50% rather than backgas. Another validation for carrying larger 50% volume. Your O2 deco expires first, so they switch to your reserve of 100%.
In respect to switching algorithms; I don't see by difference between choosing to pound the m-value or just opting to skip planned deco.
The only feasible time to adjust the algorithm more aggressive is if you've opted for a very over-conservative setting in the first place. I do that sometimes because I'm considering post-dive factors...and/or I'm on dives where I'm not in any rush to exit the water. I'm a fan of surfacing as clean as I can. For instance, swapping from GF70 to GF85. Post-dive factors can be dealt with post-dive.
But as it's been said... knocking off some conservatism isnt gonna solve any problems for lost gas.... the deco time savings will generally be irrelevant to the big picture.
