Bonaire National Marine Park
Bonaire gets - and deserves - a lot of credit for its commitment to the protection of its marine environment. The Marine Park, which surrounds the island from the high-water mark down to 200 feet, was pioneered by a diver (the famous Captain Don Stewart) back in 1979 and has been supported by diver contributions since 1990. There's great snorkeling around most of the island (look for the yellow shore-dive markers), but standouts include Sorobon in Lac Bay, 1,000 Steps, Karpata, and Klein Bonaire. In some places, the hard corals grow right to the surface, and there are still healthy stands of elkhorn swarming with fish. The annual fee is $25 for divers, $10 for snorkelers. bmp.org
Glover's Reef Marine Reserve
Glover's Reef is one of the Caribbean's rare atolls, lying some 30 miles off the Belize coast and forming a large, protected link in the vast Mesoamerican Barrier Reef (locally called the Belize Barrier Reef). Created in 1993 and named a World Heritage Site in 2000, the reserve encompasses the entire atoll, down to the 100-fathom line, with no-take areas where grouper spawn, and zones that allow sustainable indigenous fishing or snorkeling and diving. Inside the atoll's 80-square-mile lagoon, 700 coral patch reefs provide endless snorkeling and common sightings of turtles, sharks and rays. The Wildlife Conservation Society (wcs.org) operates a research station on Middle Caye, and visitors can stay at a rustic eco-resort on Long Caye (slickrock.com).
Bloody Bay Marine Park
With its tiny population and scant development, Little Cayman has seen virtually no human-caused damage to its reefs - and marine park status ensures continued protection of one of the world's most spectacular underwater attractions: Bloody Bay, on the north coast. Snorkelers here have the rare opportunity to swim over a coral cliff. Floating in the clear water at a site called Three Fathom Wall, you watch fish milling around the bottom in 18 feet of water. Fin a few yards north, and the bottom drops straight down 1,000 feet. The walls of Bloody Bay are festooned with healthy creatures - tangles of rope sponges, gigantic barrel sponges and webs of soft corals. caymanislands.ky
Venezuela
Los Roques Archipelago National Park
These 50 islands poking out of crystal-blue waters 90 miles east of Bonaire are ringed with reefs and softened by vast coral-sand flats and turtle-grass beds swarming with bonefish. Only one of the islands, Gran Roque, is inhabited, and it's there that visitors base themselves in small posadas that line the island's few sand streets. Snorkelers and divers head out with local guides in small boats to explore surrounding isl
ands and their practically virgin reefs, which received protected status in 1972 and continue to be among the healthiest and most biodiverse reefs in the Caribbean. The farther south from Gran Roque, the better the reefs. losroques.org; ecobuzos.com (for scuba divers)
Soufriere/Scott's Head Marine Reserve
As if swimming inside a volcano isn't cool enough, snorkelers visiting the southern tip of Dominica can toast to the success of this marine reserve by floating in Champagne - one of the Caribbean's most unique sights. Volcanic gases gurgling up through the rocky seabed give the shallow dive site its name, and you can join parrotfish and juvenile tropicals swimming though the bubbly backdrop. Another great snorkel spot in the reserve (established in 1998 after a campaign by local high-school students) is the top of Scott's Head Wall, on the rim of a submerged crater, with views of supersized gorgonians, sponges and brain corals. $2 park fee; dominica.dm
