Dive at Rocher du Diamant

A 175-metre plug of volcanic basalt rises out of the sea two kilometres off Pointe du Diamant, and under the waterline it is Martinique's best-known dive. Divers swim through caves and a fault that splits the rock right through, past a deep triangular cavern hung with sea fans and coral, and down steep drop-offs where schools of fish circle. The British held the rock for 17 months in 1804 and 1805, commissioning it as a warship, HMS Diamond Rock.

The currents here are strong, which makes this a dive for experienced divers rather than a first try. Several dive centres along the south coast run boats out, including one on the public beach at Sainte-Anne beside Club Med and others at Le Marin, Le Diamant and Les Anses-d'Arlet. Snorkellers can see something of it from the day boats that stop nearby.