really appreciate everyone's feedback; been having trouble looking at the revision 6 in u.s.navy diving manual - very interested in that; we plan to use nitrox, air tables, and a conservative dive plan; after our surface interval of 5 hours, our repetitive group designation should be B (NAUI tables); even with that we can go even more conservative on our dive; as a side note: 35 years ago, when diving cozumel and cayman, we routinely flew after 12 hours and i can remember(and so can my local dive master) frequently flying after 6 hours; our hydration efforts consisted of a few beers between dives; certainly not promoting any of this - but time and additional research have shown us much; at this point, we plan to make the dive and to fly 5 hours later unless the info in the navy manual changes our minds; would still appreciate any other views, comments that anyone may care to post; thanks again