anti-computer people:
Personally, I switch to my back up computer.
Both fail... same as if a backup depth gauge or watch failed... dive is over.
As for planning the dive? My computers have this groovy plan feature where it'll tell me my max bottom time at any single depth or -- and this has proved mostly just entertaining, but seems like it could be pretty cool given the right circumstances -- it can actually simulate an entire dive.
My Cobra, in fact, will even estimate about much gas I'd be using throughout the dive.
Self-educated, though. In OW they just went over the tables that seemed as outdated as an abacus to me.
