As divers, we all remember the first time something went wrong underwater.  Maybe your mask wouldn’t stop leaking or a fin strap broke at 60 feet. Maybe you put a bit too much air in your BCD or a stray current sent you drifting a little higher than you meant to go. Maybe you were paying attention to too many things at once, such as your depth, your breathing, your buddy, or your gear, and a feeling of task overload...