The single best thing about the Maldives, and usually free. A good house reef means turtles, reef sharks and a wall of fish a two-minute swim from the beach. It is worth choosing your island on this alone — some have world-class reefs, some have almost nothing.

South Ari Atoll holds one of the few year-round whale shark populations anywhere. They are filter feeders and completely harmless — you snorkel alongside the largest fish in the sea. Go with an operator that keeps its distance and limits numbers in the water.

In Baa Atoll, a UNESCO Biosphere Reserve, dozens of mantas gather to feed in a single small bay when the plankton runs — roughly June to November. Snorkel only, with permits and time limits, which is exactly why it still works.

The image the whole country trades on, and it does live up to it — steps straight down into the lagoon, and nothing but water in every direction. Even a single night at the end of a cheaper trip is a way to do it without the full resort bill.

Bioluminescent plankton that glows blue as the waves break, most often reported around Vaadhoo and other islands on dark, moonless nights. It is a natural event, not a scheduled show — nobody can promise it, and anyone who does is selling you something.

Maafushi, Dhigurah, Thulusdhoo and others have guesthouses, public ferries and dive centres — the Maldives at a tenth of the resort price. Different rules apply, including modest dress outside designated bikini beaches and no alcohol sold on the island.

A boat drops you on a strip of white sand in the middle of the ocean with a packed lunch and nothing else. It is as good as it sounds, and it is one excursion that costs about the same from a guesthouse as from a resort.

Spinner dolphins travel in pods of dozens and genuinely do leap alongside the boat. Late afternoon is when they move, so it doubles as the sunset trip. Cheap, reliable and the easiest excursion to add to any stay.

If your transfer is by seaplane, take the window seat and treat it as an excursion rather than a journey. Atolls from the air — rings of reef in twenty shades of blue — are a sight you cannot get any other way.

A proper surf destination that most visitors never notice. Consistent reef breaks around North Malé and Thulusdhoo, best from roughly March to October, with guesthouses and surf camps built around them.

The capital is one of the most densely populated islands on earth and nothing like the brochure — fish market, coral-stone mosque, traffic and life. Worth half a day if your flights leave you time, and Hulhumalé next door has an actual public beach.

Beyond the house reefs, the Maldives is a serious dive destination: channel dives with current and grey reef sharks, night dives with feeding mantas, and a handful of wrecks. Liveaboards reach the atolls that day boats cannot.