We log every diver in and out of the water and I will mark down estimated dive times. Before we leave the dive site the Captain will double check with a head count from the dive roster.

As for the PLB for an average dive boat I think it would be to expensive at $500 per unit I doubt any boat operator would be willing to invest that kind of money. Also I couldn't find a depth rating for the PLB and we usually dive from 65'-200' so this may be an issue.

It kind of boggles my mind how this happens but it does happen. You need to dive with a good boat that has a good crew & captain.

Adam