As I understand it, it's DIR if a failure of your buoyancy system won't kill you. Makes sense right?StSomewhere:Sort of back on topic, then is using a single E7-100 with an aluminum bp and a 3mm suit not DIR? That should be only 10 lbs negative with a full tank, minus the wetsuit buoyancy, correct? How much leeway is there in terms of negative buoyancy for a balanced rig and the weight of gas in the full tank?
If you can swim the thing up from depth with a total buoyancy failure, then it's OK. And I doubt you would have too much trouble swimming a full E7-100 from depth with a 3mm wetsuit.