Bonaire has 86 marked dive sites and a rich marine ecosystem that includes brain, elkhorn, staghorn, mountainous star, and soft corals; anemones, sea cucumbers, and sea sponges; parrotfish, surgeonfish, angelfish, groupers, blennies, frogfish, and yellowtails; not to mention sea horses, sea turtles, moray eels, and sea snakes. Sixty of the sites are accessible by shore and are marked by painted yellow rocks along the roadside. Forest, with an abundance of black coral, and Hands Off, with its abundant marine life, are two favorite boat dive sites, both near Klein Bonaire, the small, uninhabited island off the west coast.

Created in 1979 to protect the island's coral-reef ecosystem, Bonaire National Marine Park incorporates the entire coastlines of both Bonaire and Klein Bonaire, the small, uninhabited island opposite Kralendijk. Collecting shells or coral is prohibited, as are spearfishing and anchoring (boats use permanent moorings). Visitors are asked to respect the marine environment and to refrain from activities that may damage it, including sitting, standing, leaning, or walking on the coral. Even a thin layer of silt can prove fatal to these delicate colonial marine animals that make up the fragile living surface of the coral formations. Feeding the fish is also illegal, not to mention unhealthy for the fish. Due to safety regulations since the September 11, 2001, terrorist attacks in the U.S., diving or snorkeling near any commercial piers requires an additional permit from the harbor master (in other words, you really should go elsewhere).

Because protecting nature is taken seriously, all divers, snorkelers, windsurfers, and swimmers are required to pay a nature fee of $10 per day or $25 per year. Tags are good for 1 calendar year and also permit admission into Washington-Slagbaai National Park. A 1-day pass can also be purchased for $10 for divers; nondivers 11 and under and Netherlands residents are exempt. Tags can be purchased at all dive shops as well as the Tourism Office at Kaya Grandi 2. An orientation dive is required for all divers. For more information, contact STINAPA Bonaire (tel. 599/717-8444; www.stinapa.org).

Dive shops are numerous and highly professional. Expect to pay $45 to $50 for a one-tank dive, $70 to $80 for a two-tank dive (equipment extra), and about $100 for an introductory resort course (equipment included). Every operation offers multiple dive packages that are a much better value than the a la carte options.

Captain Don's Habitat Dive Shop, Kaya Gobernador N. Debrot 103 (tel. 599/717-8290; www.habitatbonaire.com), is a PADI five-star training facility. The open-air, full-service dive shop includes a classroom, photo/video lab, camera-rental facility, equipment repair, and compressor rooms. Habitat's slogan is "Diving Freedom": Divers can take their tanks and dive anywhere, day or night. Most head for the Pike, .8km (1/2 mile) of protected reef right in front of the property. The highly qualified staff is here to assist and advise, but not to police or dictate dive plans. Diving packages include boat dives, unlimited offshore diving (24-hr. a day), unlimited air tanks, weights, and belts. Some dive packages also include accommodations and meals. If you're not staying at the hotel as part of a dive package, you can visit for a beach dive, costing $52. A boat dive, not including equipment, goes for $62.

Divi Dive Bonaire, K.A. Abraham Blvd. 40, at the Divi Flamingo Beach Resort & Casino (tel. 800/367-3484 in the U.S., or 599/717-8285; www.diviflamingo.com), has a well-stocked shop, 24-hour access to tanks, and a reef only 18m (59 ft.) away. Divi Dive Bonaire is also fully equipped for travelers with disabilities.

Great Adventures at Harbour Village, Kaya Gobernador N. Debrot 71 (tel. 800/868-7477 in the U.S. and Canada, or 599/717-7500), is the island's poshest operation. It's upscale but unpretentious and friendly. In addition to two of the island's most beautiful boats, it boasts a first-class photo shop that rents underwater still and video cameras.

Bonaire Dive & Adventure, Kaya Gobernador N. Debrot 77A (tel. 599/717-2229; www.bonairediveandadventure.com), in addition to offering dive packages, also arranges other activities such as cycling and kayaking.

Wanna Dive (tel. 599/717-8884; www.wannadive.com) has five locations, but its biggest place is at Eden Beach Resort where you can dive right off the beach or hop on a boat and head out to the spectacular double reef at Klein Bonaire.

Thanks to shallow-water coral reefs, snorkelers can enjoy Bonaire's awesome marine environment, too. The island's Guided Snorkeling Program includes a slide-show introduction to reef fishes, corals, and sponges; an in-water demonstration of snorkeling skills; and a guided tour of one of several sites. The cost is $40 per person. Equipment rental is about $10 more. Families may want to enroll with Sea and Discover (tel. 599/717-5322; www.seandiscover.com) for a marine education experience. A real marine biologist will teach you reef ecology, fish behavior, and critter identification both in a classroom and in the water for $45. The Reef Explorers program for kids offers a half-day hands-on discovery experience for $30 per child, including transportation.

You can arrange a guided snorkeling tour through any of the dive shops listed above or through Buddy Dive Resort, Kaya Gobernador N. Debrot 85 (tel. 599/717-5080; www.buddydive.com); or Dive Inn, Kaya C.E.B. Hellmund 27 (tel. 599/717-8761). The more adventurous can purchase a map that marks all the dive sites off Bonaire, most of which are excellent for snorkeling (as well as diving) and can be reached by wading into the water.

If you are an experienced diver and have training doing reef cleanups, you can participate in a cleanup dive through Bonaire Marine Park (tel. 599/717-8444; www.bmp.org). You must send an e-mail to marinepark@stinapa.org to make special arrangements. Additionally, every few months, Dive Friends Bonaire (tel. 599/717-2929; www.dive-friends-bonaire.com), together with NetTech N.V., organizes cleanup dives. If the timing is wrong and you still want to "do your part" for the reef, check out the Reef Environmental Education Foundation (REEF; www.reef.org), a volunteer monitoring program where divers can log in and add their fish sightings to a global database used by scientists to monitor populations.

For a relaxing morning or afternoon sail and snorkel trip, board the Woodwind (tel. 599/786-7055; www.woodwindbonaire.com). For $45 (4 hr.) or $50 (5 hr.) per person, the trip includes snorkel gear, lunch, beer, and nonalcoholic beverages. Or try Pirate Cruises (tel. 599/780-9933) with Captain Mike, aboard a 56-foot private ship that offers half-day sail and snorkel trips as well as sunset or dinner cruises daily. If you are eager to see one of Bonaire's rarest inhabitants, Mike offers a turtle lover's snorkel trip aboard a 36-foot dive boat to some of the best sites for turtle encounters. All trips leave from Karel's Beach Bar Pier downtown on the waterfront, and reservations can be made there or at Zeezicht Restaurant across the street.

"The Hooker" -- The waters off the coast of Bonaire received an additional attraction in 1984. A 79-foot-long rust-bottomed general cargo ship was confiscated by the police, along with its contraband cargo, about 25,000 pounds of marijuana. Known as the Hilma Hooker (familiarly dubbed "the Hooker" by everyone on the island), it sank unclaimed (obviously) and without fanfare one calm day, in 27m (89 ft.) of water. Lying just off the southern shore near the capital, its wreck is now a popular dive site.

Note: This information was accurate when it was published, but can change without notice. Please be sure to confirm all rates and details directly with the companies in question before planning your trip.