Open Water is based on a true story as well is it not?
I must confess I've never been on a dive boat where the divers are not counted back in and their remaining air noted on the sheet........ Long may that continue!
I watched it on Five for the first time a few weeks ago, thought it was ace. Didn't see how it could sustain itself but it did. Felt very sorry for the couple, especially how their memories were rubbished to save a buck.