It isn't like these part time dive boat captains understand what a probable run time is, and they don't teach divemasters to supervise dives any more, they teach them to assist classes. (I don't know what boat, who the Captain is, or if there was a divemaster) I'm seeing a disturbing trend towards fishing boats taking divers to fill in on slow charter days, taking them for less money than they would pay for a 2 tank on a real dive boat, and the captain has no idea what he doesn't know, and isn't insured to cover divers anyway. And, he has no divemaster to advise him because if he were paying a DM, then hed be right back at charging for a normal 2 tank.
See the recent fatality on the USS Mohawk in Lee County, FL.