The Best Snorkeling in St. Croix: Buck Island and Beyond

If you ask where to snorkel in St. Croix, the answer almost always starts with Buck Island. This guide explains why, what else is worth knowing about, and how to pick the right snorkel trip for your group.

1. Buck Island Reef National Monument

About 1½ miles off the north shore, Buck Island is a National Park Service monument built around a coral reef. The NPS describes its barrier reef as one that “ranks among the Caribbean’s best”. Elkhorn coral surrounds about two-thirds of the island and creates a lagoon whose wide, shallow waters seldom exceed 12 feet deep. In the calm water behind the reef, brain corals grow so large they nearly reach the surface. Outside the barrier reef, elkhorn and star coral patch reefs ring the island, except to the southwest.

What makes Buck Island easy for beginners is the marked underwater trail. Signs along the route explain what you’re looking at, and the NPS gives the maximum depth in the coral grottoes as 12 feet. The whole monument is a marine protected area, with no fishing or collecting allowed, which helps keep the reef healthy.

You can only reach the reef by boat. Unless you have your own, that means a trip with one of the park’s authorized concessioners. Caribbean Sea Adventures is one of them.

2. The east end: Jack and Isaac Bays

If you like your beaches off the beaten path, St. Croix’s east end is worth the drive. Jack and Isaac Bays are reached by a hike down to the shore. You’ll find secluded sand, a reef to snorkel and the feeling of having a beach to yourself. There are no amenities at all, so bring water, snacks and reef-safe sunscreen.

These beaches matter for wildlife too. The NPS says Buck Island and the east end beaches (Jack’s, Isaac’s and East End Bays) hold the most important concentrations of hawksbill turtle nesting left in the Virgin Islands. Nearby, the East End Marine Park was the U.S. Virgin Islands’ first territorially designated marine protected area. The NPS says it protects roughly 60 square miles of coastal and marine resources along 12 miles of shoreline, from Green Cay on the north side to Great Pond on the south.

Shore snorkeling safety: the NPS warns about hazardous surf and crosscurrents and says not to swim alone. If in doubt, don’t go out.

3. Your own spots, on a private charter

On a private charter the plan is yours. You can snorkel Buck Island’s reef and trail on your own schedule, spend longer in the water, or ask your captain about other spots that suit the day’s conditions. We’re happy to accommodate any request that doesn’t break a National Park Service rule. Our glass bottom boat, Mile Mark, also lets non-snorkelers in your group see the reef without getting wet.

How to choose a St. Croix snorkel tour

All our Buck Island snorkel trips include snorkel gear, a lesson, a guide in the water and national park fees. The difference is time, boat and how much snorkeling you want:

The Beach & Hike and Sunday Funday trips are beach days with no reef snorkel stop. They’re great for non-snorkelers, but not if snorkeling is the goal.

When is the best time to snorkel in St. Croix?

Any time of year. The water is warm year-round, and we run trips 365 days a year. The NPS gives average highs of 84°F to 89°F, with winter lows that rarely dip below 73°F. A few things are worth knowing (NPS weather notes):

• April to June typically sees little rainfall.
• Hurricane season runs June 1 to November 30, with peak months for storms from August to October.
• Strong easterly winds can sometimes carry Saharan dust, which affects air quality.

Each day our U.S. Coast Guard licensed captains assess the conditions. If we cancel for weather, we’ll do everything we can to reschedule, and if that doesn’t work you get a full refund. The Half Day Snorkel runs at 9 am and 1 pm, so pick whichever fits the rest of your day.

Snorkeling with kids and beginners

The NPS says all Buck Island concessioners can teach anyone, especially kids, how to snorkel, and that the lagoon behind the barrier reef usually has calm water. On our trips:

• The crew teaches you on the beach before you head to the reef, which is what the NPS recommends.
• A guide is in the water with you, and not-so-strong swimmers can hold a safety ring.
• Tiny Humans 0–2 ride free on the Half Day Snorkel, and Young Adults 3–17 are $75.
• Bring a life jacket your child is comfortable in. They’re required to wear one for most of the tour.

Reef-safe snorkeling

Corals grow slowly, and the NPS lists pollution, sedimentation, warming seas and boat damage among the threats they face. Coral disease and hurricanes have also hit Buck Island’s reef in recent decades. Help protect it:

• Use reef-safe sunscreen or a sun shirt. Sunscreens with oxybenzone are prohibited on our trips (environmental notice).
• Don’t touch, kick or stand on coral. It harms the reef, and the NPS warns that cuts from sharp and fire corals infect quickly.
• Take nothing but photos. Buck Island is a no-take zone.