Maldives atolls explained: a visitor’s guide

An atoll is a ring-shaped coral reef, or a broken chain of reefs, that encloses a lagoon. Small islands of sand and broken coral build up on the reef rim, and some are big enough for villages, palm groves and an airstrip. Inside the ring the water is calm and shallow; outside, the reef drops away into deep ocean.

The word itself is Maldivian: English took “atoll” from the Dhivehi *atholhu* (އަތޮޅު), most likely by way of Portuguese.

How atolls form

The classic explanation comes from Charles Darwin, writing in the 1840s, and is still the starting point in textbooks such as National Geographic’s education resources:

• A volcano rises from the sea floor and forms an island.
• Corals grow in the warm shallows around its shore, making a fringing reef.
• Over a very long time the volcano cools and slowly sinks. The reef keeps growing upwards, so a lagoon opens between the reef and the shrinking island (a barrier reef).
• Finally the volcano disappears below the surface. What is left is the reef ring and its sandy islands around a lagoon.

Later research has refined the details, but the core idea holds: a reef survives only if coral growth keeps pace with sinking land and rising sea. That is why reef health matters so much here. Most of the world’s roughly 440 atolls are in the Pacific.

You will see two numbers, and both are right.

• 26 natural atolls. This is the geographic count, the one used by visitmaldives.com and most reference works. Some “atolls” are large rings with dozens of islands; others are tiny, or even a single island.
• 20 administrative atolls. For government, the natural atolls are grouped into 20 units. A big natural atoll can be split in two (Ari becomes Alif Alif in the north and Alif Dhaal in the south), while Kaafu brings together North Malé, South Malé, Gaafaru and the island of Kaashidhoo.
• Malé City is run as a city in its own right rather than as part of an atoll.

The government’s own atolls site lists all 20 administrative atolls by official name, from Thiladhunmathi Uthuruburi (Haa Alif) in the north to Addu Atholhu (Seenu) in the south. Across them sit about 1,192 islands; in the 2022 census, 187 were inhabited, 168 were resort islands and 106 were industrial islands.

Local government has changed recently. Following amendments to the Decentralisation Act, atoll councils were dissolved in May 2026, and local affairs now sit with island and city councils. The atoll names and letter codes are still how islands are identified in daily life.

Every administrative atoll has two names. The official one is geographic and in Dhivehi, such as *Maalhosmadulu Dhekunuburi* (“southern Maalhosmadulu”). The everyday one is a letter of the Thaana alphabet, assigned roughly north to south. The codes were introduced for radio communication between the atolls and Malé, and they stuck because they are short and easy to say.

Where an atoll is split, the code has two letters: *Alif* means north (*uthuruburi*) and *Dhaal* means south (*dhekunuburi*). So Alif Alif is North Ari and Alif Dhaal is South Ari.

You will meet the codes:

• On addresses. An island is written with its atoll code first: “K. Dhiffushi”, “B. Eydhafushi”, “S. Hithadhoo”.
• On boats and ferry signs. Registration plates and timetables often use a code letter with a number.
• In conversation. Maldivians usually say “Kaafu” or “Baa”, rarely the full Dhivehi name.

Island names repeat across the country, so the code tells you which island someone means.

These are the atolls most travellers pass through. Transfer options change, so check current schedules before you book.

A few notes on the table:

• Ari is one natural atoll split into two administrative atolls. Ask which half an island is in, as transfers differ.
• Baa‘s biosphere reserve covers the whole atoll, with core protected zones such as Hanifaru Bay, where visitor access is controlled. Read our marine life guide before you plan around mantas.
• Addu and Fuvahmulah are far south, close to the equator. They are best treated as a separate trip by air rather than an add-on to the central atolls.

Distance from Malé

Everything starts at Velana International Airport on Hulhulé, next to Malé. The closer your island, the cheaper and simpler the transfer, and the less time you lose on arrival and departure days. Kaafu and the nearer parts of Ari and Vaavu can usually be reached the same day you land, even on an evening flight.

Transfer type and cost

• Shared speedboats are the usual choice within Kaafu and to nearby atolls. They run on set schedules, so match them to your flight times.
• MTCC public ferries are the most affordable option but slow, paid in cash in rufiyaa, and on most routes do not run on Fridays.
• Domestic flights to regional airports make distant atolls practical, often followed by a short boat ride, at a higher cost.
• Seaplanes mostly serve resorts, so they are rarely the affordable choice.

Our getting around the Maldives guide explains each option in more detail.

Ferry links and island hopping

If you want to visit two or three islands, choose them in the same atoll, or in neighbouring ones, where boats link them directly. Crossing between distant atolls usually means going back through Malé. See island hopping in the Maldives for route ideas, and our 7-day local islands itinerary for a worked plan.

What you want to do

Every atoll has reefs, lagoons and quiet islands, so the differences are about access and timing. Surf breaks, manta seasons and dive sites vary by area; our guides to snorkelling, diving and surfing cover where and when.

Here is how the atoll system looks from one Kaafu island.

• Address: K. Dhiffushi. The “K.” tells boat crews and officials it is the Dhiffushi in Kaafu.
• Location: on the eastern rim of North Malé atoll, about 37 km north-east of Malé. It is the easternmost inhabited island in the country, so the sun rises here first.
• Getting there: shared speedboat in about 40–50 minutes from Malé or the airport, or the slower MTCC public ferry, which does not run on Fridays.
• Outer reef: being on the rim means the ocean side is close by, which is why surf and outer-reef trips are within easy reach.

For timings and boat options, see how to get to Dhiffushi, and use our map to see where the island sits in the atoll.