i disagree about the nitrox: if a person can't take the time to dive conscientiously and safely, nitrox will only increase their level of risk because, although the threat of DCS is lower, the threat of O2 toxicity is huge at depths like 119ft. also, having a nitrox tank might encourage some divers to behave even more irresponsibly because they feel falsely protected from the very real consequences of dangerous diving.
i'm looking at both the EANx and RDP tables. Matt's first dive (110 feet for 20 minutes) is way outside the no-deco limit on both charts. so there's no way to figure what his repetitive dive profile would be. a dive computer would credit some for time spent at shallower depths, but if you don't have a computer you have to dive tables. (it's really, really not okay to dive somebody else's computer.)
what's confusing to me is why a diver would wish to dive so far out of their level of control. sky-divers don't jump to see who can hit the ground fastest...
ADY