Trunk Bay

Trunk Bay is on the north shore of Saint John in the US Virgin Islands, inside Virgin Islands National Park — which covers about sixty per cent of the island, the result of a land donation by Laurance Rockefeller in 1956. The beach is a short crescent of white coral sand with an islet lying just offshore.

It is best known for the underwater trail: a marked snorkelling route around Trunk Cay with submerged plaques identifying coral and fish, installed in the 1960s and among the first of its kind anywhere. The reef has had a hard time since — hurricanes in 2017 and repeated bleaching events have damaged it substantially — and what is there now is a recovering system rather than the one in older photographs. That is worth knowing before arriving.

The bay itself is calm, shallow and reef-protected, with fine white coral sand and a gradual entry. Sea grape and coconut grow close to the waterline and give real shade, which is rare and valuable here. The islet is a few minutes' swim out and the trail circles it.

Facilities are national park standard: car park, changing rooms, showers, snack bar, snorkel rental, lifeguards and an entrance fee. It is the most managed beach on the island and correspondingly the busiest, particularly when cruise passengers arrive from Saint Thomas. The park's own campground at Cinnamon Bay, a few minutes east, is the cheapest way to stay on Saint John and puts a quieter beach with the same water on your doorstep.

An underwater snorkelling trail with signs on the seabed, inside a national park that covers most of the island because one man bought the land and gave it away in 1956. It is busy and it is capped and the fee is real. Cinnamon and Maho nearby have the same water and no queue.