Coral thrives along their underwater volcanic slopes, nurturing colonies of riotous color and beauty in water as clear and blue as Curacao's famous liqueur. Bonaire, though the smaller and less worldly of the two, led off this endeavor, and its dive facilities are virtually peerless.
Underwater photography is a popular pastime, too, so most shops include darkrooms and labs.
Because the reefs are so accessible, snorkeling's also superb. A long the coast, coves of fine sand alternate with rugged lava formations where the sea has carved cavernous grottos. Inland, both islands are arid and sandy, a cactus-speckled landscape known as cunucu. Bonaire's 112-square miles are occupied by 11,000 people, Curacao, at double that size, is home to 175,000 citizens of nearly 80 nationalities. Willemstad, Curacao's capital and the maritime center of the Netherlands Antilles, embraces the world's seventh-largest harbor, trafficked by yachts, trading schooners, and supertankers hauling Venezuelan oil.