old frogman
Registered
Hi Mas,
Reference the Drager FGT 5400. Some semi-closed circuit rebreathers can be converted to closed circuit rebreather for use with oxygen prior to diving, during the apparatus preparation stage. Some have a capability of switching from mixed gas to oxygen underwater during the dive. These are military grade rebreathers used for explosive ordnance disposal on nitrox or for deep lock-out from submarine, initially on nitrox and then switching to oxygen for approach to target.
The limiting factor with oxygen is that you cannot go deep, max about 45 ft for about 10 mins. Oxygen is normally used for long swims at about 15 ft max. There is always the risk of oxygen poisoning (O2 hit) on long swims.
Reference the Drager FGT 5400. Some semi-closed circuit rebreathers can be converted to closed circuit rebreather for use with oxygen prior to diving, during the apparatus preparation stage. Some have a capability of switching from mixed gas to oxygen underwater during the dive. These are military grade rebreathers used for explosive ordnance disposal on nitrox or for deep lock-out from submarine, initially on nitrox and then switching to oxygen for approach to target.
The limiting factor with oxygen is that you cannot go deep, max about 45 ft for about 10 mins. Oxygen is normally used for long swims at about 15 ft max. There is always the risk of oxygen poisoning (O2 hit) on long swims.