The Tobago Cays are five uninhabited islets in the Grenadines of Saint Vincent and the Grenadines, in the eastern Caribbean, lying inside a four-kilometre arc of coral called Horseshoe Reef that takes the Atlantic swell and leaves a lagoon of turquoise water behind it where green turtles graze the seagrass in water shallow enough to stand in, and they are reached only by boat from Union Island or Bequia. The cays are a marine park, and the anchorage is in open water behind the reef, where the boats slip through a gap and lie with no land at all to windward, only a white line of surf a few hundred metres off and the swell dying before it reaches them; the turtle-watching zone lies off the southwestern shore of Baradal, where the green turtles feed on the seagrass a few metres down and surface to breathe beside the swimmers, and the inner edge of Horseshoe Reef is drifted on the current a few metres above the coral, since the outer face takes the ocean. The white floor that turns the lagoon turquoise is not ground-up rock but the reef itself, coral broken and ground by the sea and the parrotfish.
Petit Tabac lies alone on the ocean side of the reef, a curve of white sand, a stand of palms and nothing beyond it but open Atlantic, and it played the island where Jack Sparrow was marooned in the first Pirates of the Caribbean film in 2003. Park rules pen the vendors onto one strip of sand on Petit Bateau, where the boat cooks set up grills under a couple of tents and take orders for grilled lobster from boat to boat through the day, eaten on the beach at sunset. Hawksbill and green turtles haul out to nest on the cays from June, inside the hurricane season, and Beryl crossed the islands as a Category 4 in July 2024, wrecking Union Island. The Tobago Cays are a lagoon with a reef for a wall, and the turtles are its tenants.