Unfortunatley, only the airlines (U.S. Air & a couple others) offer travel insurance cancellation for business reasons (there is a 50-50 probability I will have to cancel at the last minue) (thanks for your reply in the other thread I started Natasha). So I am reduced to going with them. Unfortuantley, those pacakge trips are (1) expensive (2) don't include diving so they are more expensive (3) are to very few diving locations. So we are going to try to pick something up last minue. Most likely we will end up hopping down to S. Florida again. However, we may get lucky and find cheap last minute tickets to somewhere like Belize, Honduras, or T&C with reasonable hotels still available.
I checked out Akumal, and it looks very nice, its also not super popular so maybe everything won't have sold out for a last-minute trip.
The live-aboards also look fantastic, but there is no way I could reserve one and then cancel at the last minute. When I move on to a more humane job the first thing I am doing is hopping on a live-aboard. (I really want to dive Cay Sal in Bahamas).
Unfortunatley, what started as a well-considered process of setting up a trip will be left to the fates of Priceline.