Corsica — Lavezzi & Bonifacio

Diving here is a crossing as much as a dive. Boats leave Bonifacio, run out of the inlet into the strait, and the sea state decides the rest: on a calm morning the exposed rocks are on, and when the wind funnels through the Bouches everyone falls back to the sheltered coves on the Lavezzi side, Cala di Grecu among them. Plans change at the quayside rather than the night before, so keep the week loose and allow more days than you need dives.

A typical dive works a moderate profile across the rock — start deep on the outside of a boulder field, climb through the gaps, and finish the last stretch over sand in the shallows where the light is strongest. Granite weathers smooth instead of splitting into the cracked ledges limestone gives you, so life concentrates in the seams and undercuts. That is worth slowing down for, because the wide-angle scenery will otherwise pull you straight past it.

Mérouville is why most people book, and the dive is unusual in shape: the plan is to settle on the plateau at around 25 m and stay put for most of the bottom time rather than to cover ground, which is not what a reef dive normally asks of you. Le Sec du Toro is the opposite, a submerged rock rising to within about 5 m of the surface with real current across it, taken only when conditions allow. Between the two, the area suits confident Open Water divers happy to spend a whole dive watching one thing closely.