Socotra

Diving here is expedition logistics first and diving second. Trips are put together by a handful of operators who arrange permits, ground transport and food, and most nights are spent at campsites rather than hotels, with basic rooms in Hadiboh at either end. Entries are off the beach or from open outboard boats launched through the shorebreak. Compressor capacity is limited and fills are agreed in advance, so the day gets planned around how many tanks exist rather than around what the reef could give you.

The ground underwater is not classic atoll reef. Socotra is a continental fragment rather than a coral island, and the coast largely continues below the surface as rock slope, boulder and rubble with coral growing over it, mostly at depths a single tank handles easily. Dihamri, on the north coast, is a community-managed protected area with a campsite above it and boat dives below, which is why most trips dive it more than once. Ras Erissel at the eastern cape is the other proposition: exposed, current-swept, water that can run noticeably cooler, and dived only when the sea allows.

The southwest monsoon shuts the sea from June to September and nothing is attempted in those months; the rest of the year is workable, with March–April and October–November calmest and the winter months usable but windier. Kit has to be self-supporting — spares, tools, anything a compressor cannot fix — because little is replaceable on the island and the next flight out is never a same-day option. In practice it suits travellers whose trip is really about the island itself, the endemic flora and the interior, with dives taken on the days the sea permits.