I watched the film last night after recording it on Sky+. I must admit it was so slow I was tempted to fast forward, but didn't. I knew it was based on real events, but hadn't read up about the ending, so I was waiting for the couple to be found, especially when the helicopter set off. I was quite shocked and sad that neither of them survived.
Like others have said, it lacked dramatic incident, perhaps the makers stuck too closely to the true story. I hope their relatives sued the boat company for their incompetence. But the film was very careful to show how the couple wanted to keep themselves to themselves, nobody else spoke to them, and the person counting the divers back wasn't around to notice that after two people came back up early, the man without the mask was then able to borrow one and dive, along with the guy who came back up. It all looked very casual, though. Can you imagine if this happened in England, we'd never hear the end of it?