So this couple was diving with us over the weekend, four dives Saturday and two on Sunday. They were both diving 36 mixes at max depths of about 65 ft on each dive for about one hour each dive with about 45 minute interval between dives 1 and 2, about a two and a half hour interval between dives 2 and 3, 45 minutes until dive four, like sixteen hours between 4 and 5 then after a 35 minute interval between dives 5 and six we checked available bottom time at 60' on their computer's planner... 34 minutes for him, 36 minutes for her. Whoa. They had Suunto Vypers, which I know are conservative... but that seemed really really conservative. I dove with them every dive my computer was giving me 74 minutes, the other guy we were diving with didn't do dives 3 and 4, he had 82 minutes. From what I see both on the boat and on the board they seem to be reasonably popular, so maybe there's something about them that I'm missing.