Have you ever gone into your third "third"?

[Duncan Price]

Occasionally - when things go wrong - not matter how careful you are, they will. That's what its there for. On occasion the remaining working tank pressure has been so low on surfacing that I've been able to remove the regulator without turning the cylinder valve off.

Mind how you go and happy new year.

[FW]

My worst case was on a single tank. The tank O-ring blew, and I got out holding my breath for the last 50'. The next worse was loosing the line, finding it, and exiting with just under a third remaining. Now I usually end dives with 2/3 remaining.