I specifically don't agree (and know, as an attorney) that because you are a DM or an instructor for that matter, that you owe any legal duty in a recreational dive situation on which you are not working: you just don't, legally or morally. Also, I've yet to see any dive operation ask an instructor (much less a divemaster) to "help them out" with their responsibilities to oversee divers on a rec. trip: it is simply unheard of, and, in fact, the opposite is true (they prefer that you stay out of the way and not offer any advice). I have been on trips and maybe wore an instrictor shirt or something, and any time a diver asked me a question, I refer them to the divemaster of the dive op or the captain of the boat. First rule of diving for "professionals": if it's not your boat or dive group, keep your opinions to yourself. So, don't let any of that fol-de-rol deter you: go for it!!!! Personally, I always bring my instructors card, so that I am shown the proper deference by the Divemasters, at least with respect to my own dive-related decisions for me. Otherwise, I keep my mouth shut....