We don't dive so no advice there. However...Mata Chica...we have stayed there twice in 2003 and are planning a third trip for spring 2004. It is fabulous. The ocean front casita's are wonderful, the fishing is wonderful, and the food (chocolate souffle) is beyond words. I can not recommend this wonderful resort enough. We have traveled to Barbados and Bermuda. Nothing compares to Belize and Mata Chica!