You'll like this one, Jim:
I work on the crew of a local NJ dive boat. Here in NJ the boats are not "dive operators" in the traditional sense, but rather we are essentially "a ride to the wreck site and back." While we aren't responsible for your dive plan and we don't accompany passengers on their dives we do ask for run-times and record when everyone enters and exits the water.
So a few weeks ago we're out on a wreck laying in 140fsw. Once we're tied in, I start asking for run-times. I ask one of the passengers how long he'll be down for...
He: Just put me down for the same run-time as my buddy
Me: Who's your buddy?
He: Um, uh, I dunno...
Did you let him dive? And if so did he come back up?