You might find these similar threads helpful ...

http://www.flyertalk.com/forum/Forum63/HTML/002509.html

http://www.flyertalk.com/forum/Forum63/HTML/001788.html

While my experience is limited to the Casa Magna in Cancun (which IMHO can be considered Caribbean), it was right on the beach, as was the JW right next door.

Enjoy your trip!