Just to point out that in this case having a buddy wouldn't of helped. There would of been two lost divers. The blame lies with the captain of the boat and the dive plan.
My .02
Jack
I think there is some question about how the captain of the boat lost the divers but I'm not willing to say the blame lies with the captain.
I'm wondering, how experienced were the divers. I have always wanted to go to Tahiti. A few years ago I looked at what the dive conditions are like and realized I was not prepared to dive there. I've been taking the time to learn drift diving, getting in better shape, etc. Was this the first drift dive for these tourists? Did they mislead the dive operator that they were more skilled just so they could go on the dive?
Drift dive, strong current, night dive. A lot to deal with if you are a novice diver.
Did they stay as a group? If the current is heading north, the group goes slightly east and one diver goes slightly west, which bubbles does the boat follow? Won't it have been worse for the boat to save one diver and lose three?
I would suspect the boat captain did the best of a bad situation. Once the divers are in the water it is hard for the boat captain to deal with problems. Who was responsible for the dive briefing? If it was the captain then I would be looking more at the captain. During the briefing, did everyone have a SMB? Where log books checked? Did they emphasize how important it was the group stay together? Why did they wait until everyone was out of air before they thumbed the dive? I would have expected the briefing to cover when the dive was to end, i.e. surface with 500 PSI. Dive should last XX minutes. If you are running out of air, go a little shallow to extend bottom time. Or was the problem that the other three divers went shallow and the current was faster so the fourth diver got left behind?
Why didn't the fourth diver's buddy stay with him?
What little information there is on this story leaves some questions unanswered. The most likely answer to those questions hint at inexperienced divers. Was the dive operator aware of the inexperience? Did they have a bad feeling but didn't call the dive because they didn't want to lose the money? Who made the call to do the dive? Or more to the point, did someone have a bad feeling about this dive and didn't call it? If that person was not the boat captain then they are partly to blame as well.
Did no one have a bad feeling and the tourist just convince the dive operator they could handle the dive when they could not? I've seen some really crappy divers who could sell a fridge to an Eskimo. They'd use their sales skills to sell themselves as highly experienced divers.