Buck Island Reef National Monument, St. Croix

Buck Island sits about 1.5 miles off St. Croix's northeast shore — close enough to see from Christiansted waterfront, far enough to feel genuinely remote. The island itself is a small, uninhabited cay with sea grape trees, white sand beaches, and nesting seabirds. What makes it extraordinary is what surrounds it: one of the finest barrier coral reefs in the Caribbean, protected since 1961 as a US national monument.

President Kennedy's proclamation designated it a national monument, and in 2001 the protected area was dramatically expanded to cover over 19,000 acres of surrounding ocean floor — making it one of the largest underwater national monuments in the country.

The Reef

The reef wraps around the island's east end in a horseshoe shape, creating a sheltered lagoon on the inside and a dramatic wall on the outer edge. The barrier structure — a ridge of living coral rising close to the surface — is what makes this reef different from the fringing reefs common elsewhere in the territory. The lagoon inside the barrier sits in 5 to 12 feet of water; the outer wall drops steeply to deeper water.

Visibility in the lagoon is regularly 60 to 80 feet. The coral coverage is among the highest in the USVI — elkhorn and staghorn coral, which have declined sharply across the Caribbean due to bleaching and disease, are present here in quantities rarely seen elsewhere. Hawksbill turtles feed on sponges along the reef face. Green turtles nest on the beaches.

The Underwater Snorkel Trail

The marked snorkel trail at Buck Island loops through the lagoon with numbered underwater stations identifying coral species, fish, and features of the reef structure. The trail is designed for beginner snorkelers — the water is shallow, the current is generally mild, and the markers give direction through the reef. Most charter operators guide guests through the trail as part of their tour, with a snorkel briefing before entering the water.

The Island

After the snorkel trail, most tour groups land on the island's west beach for a break. The beach is pristine — no development, no vendors, no permanent facilities beyond a few picnic tables and a composting restroom maintained by the NPS. The sea grape shade at the back of the beach is the best place to wait out the midday heat. A short trail climbs the island's ridge for a view over the reef and back toward St. Croix.