I have a couple of suggestions. If you are assuming that a single supplement exists based on the web site, e-mail the resort directly and see if they will give you a package for one person. I've done that before. If they are having a slow week, they might do something for you. The single supplement often exists to help the resort cover the fixed charges, typically the room and a rental vehicle (when included). When I go to Belize and Roatan alone, I usually buy the room by itself and buy my diving and food elsewhere. It's usually quite reasonable. Also, with the economy being in a troubled state in many parts of the world, you might find that some resorts would be more amenable to a discount for a single person. It never hurts to ask.