To quote the Halcyon owner's manual:
"You should be certain through in-water testing prior to the dive that. without any air in your buoyancy compensator, you are capable of swimming against the weight of you (sic) configuration with full tanks and all weight in place. You need to verify that you are able to manage your scuba configuration in the event of a buoyancy failure"
I'd add to that that you should carry some ditchable weight, and an SMB; I recently switched to an alloy BP to allow for some ditchable weight (I previously used a SS BP and didn't need any additional weight - with no/3mm springer wetsuit)
So based on the above, I don't see the need to use a double bladder (for my diving anyway)
Thanks also to Nemrod (sb poster) who assisted me in coming to this solution
"You should be certain through in-water testing prior to the dive that. without any air in your buoyancy compensator, you are capable of swimming against the weight of you (sic) configuration with full tanks and all weight in place. You need to verify that you are able to manage your scuba configuration in the event of a buoyancy failure"
I'd add to that that you should carry some ditchable weight, and an SMB; I recently switched to an alloy BP to allow for some ditchable weight (I previously used a SS BP and didn't need any additional weight - with no/3mm springer wetsuit)
So based on the above, I don't see the need to use a double bladder (for my diving anyway)
Thanks also to Nemrod (sb poster) who assisted me in coming to this solution