Speaking of exceeding depth limits....a few years back, at the shop I USED to work for, one of the other guides had a customer "get away from him" and momentarily drop to about 50m/165'. Not a good thing to let happen, of course, but the (probably narced) diver was brought up into shallow water, where she & the guide spent a long time....just like a deco dive, even though in the short time she was at depth, it's quite possible she never went into deco (it was at a "swim through" where the deep time is normally just a few minutes.) Anyhow, she was fine, no DCI symptoms or anything at all. But the boss saw "50m" in her log book, and for the next couple years, NO CUSTOMER could ever go past 24m/80'. As the most popular dive site in Guam (the Blue Hole)...where the incident occurred, by the way....has an opening at around 35m/120', none of the customers from that shop could go through it....made for a lot of disgruntled divers, especially the ones with hundreds of dives who'd been through there before. The worst part is that none of these people were ever told in advance that "the new shop rule is 24m max for EVERYONE," giving them no chance to "bail out" in advance. I DID see quite a few customers changing dive shops on the next day, though!