But more than just sizzling sand, Buck Island Reef National Monument is a snorkeling superstar. This national treasure has grottos that visitors can snorkel along as part of an underwater trail.

Located about 1 1/2 miles off the coast of St. Croix, Buck Island is the go-to spot for scuba diving and snorkeling. Managed by the National Park Service, the island is fringed with a barrier reef ...