Isla de la Juventud & Punta Francés

All the diving runs from one place: the Centro Internacional de Buceo El Colony at Marina Siguanea, on the Ensenada de la Siguanea on the island's south coast. The Punta Francés park lies 16 nautical miles from the marina, and every site is roughly an hour away by boat. Boats leave every morning, and afternoon trips run only for night dives. Groups are made up by level, transfers from the Hotel Colony to the centre are included, and trips cancelled for weather are not fully refunded.

The park's seabed is limestone reef with tunnels, channels and underwater valleys, communities on both the deeper reef and the shallows, and ledges and caves cut into the platform. On the reef front, black coral grows unusually shallow on the slope, with groupers and snappers around it; Pared de Coral Negro carries its cluster at 30 m among sponges. Barracuda and turtles are part of the reef fauna, and queen conch and spiny lobster are among the park's most significant species. Wreck divers have Bajo de Zambo, with more than 70 hulls counted.

The island suits divers who want calm, clear water and a protected national-park reef, and who accept that one centre and one marina set the terms: an hour each way, a card and logbook checked at the desk, and no second operator to switch to. A hyperbaric chamber sits at the centre itself. Within reach of the marina lie 39 sites, with more than 20 caves, canyons, vertical walls and several sunken boats among them, and every dive is run as a multilevel dive.