Visit Los Roques

Coral islands and old Swahili towns.

Granite-boulder islands in the Andaman Sea with some of Thailand’s clearest water and best coral.

Untouched Red Sea reefs and islands.

Indian Ocean islands and sandbars.

Turtle-rich reefs off Moheli.

Laid-back pair of jungle islands with clear water and cheap beachfront snorkelling.

Three tiny car-free islands off Lombok — turtles, reef bars and no traffic at all.

Ras Mohammed’s coral walls and the Thistlegorm wreck, with visibility so clear the reef looks lit from within.