Learn to scuba dive free, receive a complimentary education in tropical marine biology, and get to help save the threatened coral reefs of Southeast Asia and Central America at the same time?
If that strikes you as an attractive prospect, contact either Coral Cay Conservation or Operation Wallacea. Both organizations are run out of Britain, and both require volunteer divers to help survey coral reefs (and rain forests) with a view to establishing marine sanctuaries or desperately needed conservation-management plans.
CCC began its reef-survey programs in the Central American nation of Belize. The barrier reef off Belize is to the Western Hemisphere what Australia's great barrier reef is to the East: the biggest and the best.