Buck Island Reef
National Monument
Virgin Islands
Park Photo
NPS photo

Six thousand feet long and a half mile wide, uninhabited Buck Island rises 328 feet above sea level 1½ miles off the northeast side of the island of St. Croix in the U.S. Virgin Islands. Five miles from Christiansted, 19,015-acre Buck Island Reef National Monument includes the 176-acre island and 18,839 acres of submerged land and coral reef system. First protected in 1948, the area was proclaimed a national monument in 1961 and expanded in 2001 to preserve "one of the finest marine gardens in the Caribbean Sea." The park is one of the few fully protected marine areas in the National Park System. Endangered and threatened species living and nesting here include the brown pelican, least tern, and hawksbill, leatherback, and green sea turtles. Buck Island formed from uplifted and tilted volcanic ash originally deposited in the deep sea. Two-thirds of this tropical dry forest island is surrounded by an elkhorn coral barrier reef. The entire Monument is closed to all fishing and collecting activities, and anchoring is only allowed off the deep sand beach. Off the east end of the island a snorkel trail with underwater interpretive signs meanders through coral grottoes out to the forereef. Unique elkhorn coral patch reefs, resembling haystacks, are scattered along the outside of the forereef and rise nearly to the water's surface from the seabed as much as 40 feet below. Snorkelers encounter colorful parrotfish, French angelfish, and blue tangs. Concessioners offer daily half- and full-day tours to Buck Island from St. Croix for snorkeling and other activities.

Coral Reefs

Coral reefs are complex colonies of individual animals called polyps. These produce carbonate skeletons cemented together by blue-green algae, resulting in massive but surprisingly fragile formations. Polyps are filter feeders eating floating plankton they trap in their tentacles. As polyps die, new ones expand the reef by growing on their remains. Polyps enjoy a mutually beneficial relationship with algae living inside them. This efficient symbiosis makes coral reefs rich with life. Coral reefs support an incredible diversity of animal and plant life. Coral reefs have existed for millions of years and are as ancient as rain forests.

Buck Island's Barrier Reef

Buck Island Reef's underwater scene taxes human perception with the abundant variety of shape, pattern, color, texture, and movement. Its barrier reef ranks among the Caribbean's best. Its thick, branching elkhorn corals push their sheer mass to 30-foot heights. Like fortress walls corals rise off the sea floor and dominate the underwater world. The irregular arc of reef surrounding Suck Island's northern and eastern shores creates a lagoon between reef and island. Wide and shallow lagoon waters seldom exceed 12 feet deep, and the protecting reef moderates the wave action. In the calmer waters of the lagoon, brain corals grow larger, nearly reaching the surface. Seaward of the barrier reef, elkhorn and star coral patch reefs occur around the island, except to the southwest.

Fragile and Endangered

Worldwide, coral reefs are fast disappearing. They are slow-growing and vulnerable to pollution, sedimentation, overfishing, warming of the seas, and boat damage. Buck Island's reef system shows significant impacts from a variety of coral diseases and undetermined environmental factors. These cause corals to reject the algae that help nourish them, bleaching tissues. If severely affected, the corals die. Because corals thrive only in a narrow range of conditions, biologists see their plight as a planetary danger signal.

Buck Island Reef National Monument provides protected habitat for several threatened and endangered species, terrestrial and marine. Brown pelicans feed in the nearshore waters and nest on the island's north side. Research on hawksbill turtles provides valuable information for their survival in the Caribbean. Human introduction of the mongoose and rat, exotic species, may have eradicated the St. Croix ground lizard.

Protecting Your Park

Please treat Buck Island and its reefs like endangered species. All watercraft must follow boating regulations. Fishing and collecting activities are prohibited in the entire Monument. Before you set out review park regulations at the National Park Service visitor contact station at the Christiansted National Historic Site. Park kiosks at West Beach and Diedrichs Point shelter describe regulations and natural attractions in more detail.

Waterskiing, jetskiing, and spearfishing are prohibited. Anchoring is prohibited in the lagoon; boats must pick up a mooring. Scuba diving is prohibited at the underwater trail but allowed at the two scuba moorings in the north lagoon. Corals are not rocks but fragile skeletons. Do not stand or hang on corals. If you tire while snorkeling use the rest floats. Don't feed fish. On the island: The island closes to visitors at sunset. Pets, vehicles (except wheelchairs), artificial light, camping, glass containers, generators, and loud music are prohibited. Build fires only in the grills provided at the picnic areas by the National Park Service. Digging, tent poles, beach umbrellas, and stakes are prohibited on beaches.

Safety Tips for Sea and Shore

Local custom and town ordinances require that you wear shirts or coverups in Christiansted. Bathing suits alone are not acceptable. Avoid sunburn hazard: use sunscreen (SPF 30 minimum is recommended), hat, and coverup clothing. An average Buck Island tour puts you in sunlight four hours, ample for severe burns despite cooling trade winds. Bring a bathing suit, shoes (topsiders, sandals, or flip-flops). and towel. A concrete pier for National Park Service operations and passenger off-loading provides wheelchair access. Reef and marine hazards: Shallows and reefs near shore contain sharp corals, stingrays, spiny sea urchins, fire coral, fire worms, and barbed snails. Cuts from marine organisms infect quickly, so clean and medicate them. Portuguese man-o-war and sea wasps, both stinging jellyfish, are rarely found here. Barracuda and sharks, if encountered, should be treated with caution but are not usually aggressive toward snorkelers. Hazards ashore: Stay on the beach or designated paths to avoid hazardous vegetation. Contact with poisonous manchineel trees (sap, leaves, bark, and fruit resembling small green apples) causes chemical burning. To touch your eyes after such contact causes swelling or blindness. Christmas bush looks like holly, but it causes contact dermatitis, and stinging nettle is painful. There are several other trees, cactuses, and other plants bearing thorns or barbed hairs to avoid. Beware of centipedes, scorpions, biting spiders, and ants.

Visiting Buck Island and Its Reef

park map
(click for larger map)

Buck Island information is available at the National Park Service visitor contact station at Fort Christiansvaern in downtown Christiansted. Six concessioners offer trips to Buck Island from St. Croix under permits. Make reservations by phone or in person. Half-day trips are 9 a.m. to 12 noon and 1 to 4 p.m.; full-day trips 9 a.m. to 2 p.m. Most tours provide you 90 minutes for swimming and snorkeling, with the equipment provided.

Beginners can snorkel Buck Island's coral grottoes with advice and a short lesson from the boat crew. Guides take six visitors at a time on the underwater trail—closed sunset to sunrise—whose signs tell what you see. Maximum water depth in the grottoes is 12 feet. Always snorkel with a buddy and keep well in front of moored boats. Scuba diving is allowed in the Monument only at two designated scuba moorings: 30- to 40-foot shallow dives go through haystack formations of elkhorn coral.

Private Boating
Taking your own boat to Buck Island? Get information and anchoring permit at the National Park Service visitor contact station in Christiansted. Vessels over 42 feet should anchor at West Beach and visit the underwater trail by dinghy.

Picnic Areas
At West Beach and Diedrichs Point there are picnic tables, charcoal grills, and vault toilets. Diedrichs has a 20 x 20-foot shelter. Take all trash off the island with you. Firewood may no longer be gathered in the park. Do not empty ashes from the grill on the ground; grease attracts biting ants. Put cooled ashes in container/plastic bag and take them off island. If you must leave ashes not cooled, extinguish them with sand and leave them in the grill.

Walking Trails
A marked hiking trail from either Diedrichs Point or the West Beach picnic area crosses the island (45 minutes at a walking pace). Wear shoes and a shirt and bring drinking water. From West Beach the trail goes through lowlying beach forest over gentle hillsides with turpentine and pigeonberry trees to the island crest. A side trail to an observation point affords views of coral reef and darker, deeper water farther out, as the island's underwater shelf falls off into the Puerto Rican trench. 5,000 feet deep. The main trail goes down the south side in small switchbacks through frangipani trees, organ pipe cactus, and bromeliads. It ends at Diedrichs Point for an easy walk on the shoreline back to West Beach. For those less energetic. West Beach trail offers a hike through a manchineel forest to giant tamarind and sandpaper trees. Return via the water's edge to the picnic area.

Research and Monitoring
For more than 30 years the National Park Service and scientists have studied the Buck Island ecosystem. Monitoring and research also focus on fish and fisheries; sea turtles, brown pelican, and least tern nesting; visitor activity impacts; effects of hurricanes and human-caused disasters (ship groundings, oil spills) and of recovering from them; managing exotic plants; reintroducing native plants; and eliminating/controlling exotic predators—mongoose and tree rats.

Hurricane Hugo (1989) forced long-term, dramatic changes in both island and marine systems, with sustained 150-mph winds gusting to 204 mph. More than 80 percent of the beach forest was killed—but left standing. Hawksbill turtle nesting areas were disrupted. Scouring and pounding by storm waves destroyed most of the south barrier reef; most of the reef crest was relocated 90 feet landward, narrowing the south lagoon.

Monitoring of the coral reef's recovery continues with dramatic signs of elkhorn coral regrowth beginning in 2000.

On St. Croix, Christiansted National Historic Site preserves Danish-era architecture, and Salt River Bay National Historical Park and Ecological Preserve offers tropical land and water ecosystems as well as evidence of 2,000 years of human history.

Source: NPS Brochure (2004)


Buck Island Reef National Monument — December 28, 1961
Protected Area, Municipality of St. Croix — 1948

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Brochures ◆ Site Bulletins ◆ Trading Cards expand section


Buck Island Fish and Shellfish Populations Biosphere Reserve Research Report No. 26 (William Tobias, Eric Telemaque and Michael Davis, 1988)

Coral Reefs in the U.S. National Parks: A Snapshot of Status and Trends in Eight Parks NPS Natural Resource Report NPS/NRPC/NRR-2009/091 (Nash C. V. Doan, K. Kageyama, A. Atkinson, A. Davis, J. Miller, J. Patterson, M. Patterson, B. Ruttenberg, R. Waara, L. Basch, S. Beavers, E. Brown, P. Brown, M. Capone, P. Craig, T. Jones and G. Kudray, April 2009)

Foundation Document, Buck Island Reef National Monument, U.S. Virgin Islands (August 2017)

Foundation Document Overview, Buck Island Reef National Monument, U.S. Virgin Islands (January 2017)

General Management Plan/Environmental Impact Statement, Buck Island Reef National Monument Draft (March 2012)

General Management Plan Newsletters: No. 1 — June 2004No. 2 — July 2005No. 3 — March 2012

Geologic Resources Inventory Report, Buck Island Reef National Monument NPS Natural Resource Report NPS/NRPC/GRD/NRR-2011/462 (K. KellerLynn, November 2011)

Natural Resource Condition Assessment, Buck Island Reef National Monument NPS Natural Resource Report NPS/BUIS/NRR-2022/2380 (Danielle E. Ogurcak, Maria C. Donoso, Alain Duran, Rosmin S. Ennis, Daniel Gann, Alexandra G. Gulick, Paulo Olivas, Tyler B. Smith, Ryan Stoa, Jessica Vargas, Anna Wachnika and Elizabeth Whitman, May 2022)

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Buck Island Reef National Monument

Last Updated: 25-Jun-2022