When I dove in Puerto Rico, I had just gotten my trusty Garmin eTrex GPS receiver and was all excited to use it. However, the small, and excellent, dive company we went through in beautiful (if small and empty) Parguera, was non-too-keen on my logging the exact locations of their coveted dive locations.
As I came to understand, their knowledge of good dive locations was the IP (intellectual Property) and really gave value to their company. Of course, on the Carribbean side of Puerto Rico, I imagine there are many, many good dive spots.
Well, I guess in the lingo/jango we can all this open-diving location, but you can get your fill of GPS diving sites at Diving Destinations.net. Well, as long as your fill is 515 sites (to date).