Atolls of the Maldives

This article discusses the geographical atolls of the Maldives. See Administrative divisions of the Maldives for the administrative units also known as atolls.

Geographic distribution of the Natural Atolls of the Maldives

The Maldives are formed by a number of natural atolls plus a few islands and isolated reefs which form a pattern stretching from 7 degrees 10' North to 0 degrees 45' South.

The Maldives is a long and narrow country formed by 22 natural atolls plus a number of islands, which could be said to be smaller atoll formations. All land above the surface in the Maldives is of coralline origin. The atolls of the Maldives form a quite regular chain and, especially in the northern and central atolls, an arrayed structure is apparent. There are broad and deep channels in between some atolls.

The origin of the word atoll itself is in the language of the Maldives. 'Atoll' (from Dhivehi 'atholhu') is now used in many languages worldwide.

Traditionally, Maldivians call the atolls ending in '-madulhu' or '-mathi' by their name without adding the word 'Atoll' at the end. For example, it is correct to write simply Kolhumadulhu, without adding the word 'Atholhu' at the end. This is also the case in the atoll known as Faadhippolhu.

The atolls of the Maldives are very complex structures and formerly they were very dangerous for navigators. In 1834-36 British Captain Robert Moresby undertook the laborious and difficult cartography of the Maldive Islands, drawing the first accurate maritime charts of this complicated Indian Ocean atoll group.

These Admiralty charts were printed as three separate large maps by the Hydrographic Service of the Royal Navy. Although they contain a few errors, Moresby's charts were so good that they were favoured by Maldivian pilots navigating through the treacherous waters of their atolls until the 1990s.

Nowadays there are more accurate maps of the Maldives based on satellite surveys. However, Maldivian navigators still claim that Commander Moresby's charts provide a wealth of data that the modern maps don't give. At the time that they were drawn, the maps of the Maldives were deemed of such a high quality that they were inspected personally by Queen Victoria.

Owing to the many beautiful diving grounds of the numerous atolls of the Maldives, this country has been marketed as a prime destination for scuba divers worldwide. Hence, during the last couple of decades many guides and maps of the best diving spots have been published and some of them are very accurate and give a wide array of useful hints.

Atolls of the Maldives: physical description

The list below is a description of the geographic atolls. Some atolls are described in groups:

Thiladhunmati group

1. Ihavandhippolhu Atoll is the northenmost atoll in the Maldives. It is a small natural atoll 22 km in length. It has 25 islands lying all around the boundary reef. One long barrier reef forms the western side of the atoll. There are several coral patches in the lagoon and the general depth in the centre is 20 to 30 fathoms (35 to 55 m). Ihavandhippolhu is bounded in the north by the broad channel known as Maliku Kandu which seperates the islands of Maldives from those belonging to India.

2.Thiladhunmati, or Tiladummati in the Admiralty Charts, is a very open, atypical atoll without a clearly delimited lagoon. It stretches SSW for 76 km and contains nearly forty islands generally of a fair size. Kelai, a large island forms a prominent point in the NE of this atoll. The western boundary has fewer islands but more isolated reefs or micro-atolls (faru), with wide passages between them. The German explorer Hans Hass observed the formation of this phenomenon called 'micro-atoll' by Porites corals in the Maldives. Faru is the Dhivehi word for these reef structures. Its lagoon has few shoals, but many large faru, often topped with islands; the average depth is from 24 to 18 fathoms (44 to 33 m).

Miladhummadulhu group

1. Māmakunudhoo or Makunudhoo (Malcolm Atoll in the Admiralty Chart) is the westernmost atoll in the maldives. A large reef with lagoon, 27 km long with and average breadth of 5 km. It has only one inhabited island , Makunudhoo and three other islands (namely Innafushi, Fenboahuraa and Edipparufushi) and it lies 15 km west of the NW part of the Miladhummadulhu group. It is said to have been unknown to non-Maldivians previous to the 1834-36 survey of the Maldives. According to the locals, many ships have been lost on its barren reefs with crew, cargo and all. These include the Persia Merchant (August, 1658), Hayston (July, 1891), George Reid (September, 1872) and many more. Owing to the violence of the surf and the perpendicular sides of the reef scarcely a vestige of the wreck remains after a few hours. The lagoon is quite deep but it is full of coral patches.

2. Miladummadulhu, a large, open atoll with isolated reefs, is almost a continuation of Thiladhunmati. Both atolls are on the same plateau of soundings, and the islands limiting their western sides form a continuous chain. This atoll’s length is 81 km and it contains 101 islands. The general depth of the centre of this atoll is 20 to 25 fathoms (37 to 46 m) and the bottom is sandy. Along its western edges there are not many islands, but more detached reefs with shallow lagoons (vilu) which seldom exceed 10 fathoms (18 m) in depth. Vilu is the Dhivehi word for these lovely shallow lagoons.

Faadhippolhu

Faadhippolhu is a smaller atoll with a well-defined barrier reef to the east, on which the NE monsoon (iruvai) breaks with violence. Its western side has farus and reef patches. There are about 52 islands, of which only 5 are inhabited. The lagoon is fairly open and its general depths are from 25 to 30 fathoms (about 50 m). Its bottom is sandy and there are a number of coral patches and sunken reefs dotting it, except for the south-eastern side.

Maalhosmadulhu group

Malhosmadulhu Atoll seen from space. "Fasdutere" and Southern Malhosmadulhu can be seen very clearly in this picture

This is the most complex group of the whole archipelago.

1. Alifushi. Alifushi and Etthingili (Powell Islands in the Admiralty Chart) stand on a detached reef of their own with very deep waters (no sounding) between this faru and the northern end of the main Atoll.

2. Northern Maalhosmadulhu Atoll is 71 km in length from N to S, and 26 km across at its broadest part. Its western fringe is composed of a series of round or oval reefs (farus) irregularly placed (a feature peculiar to all the larger Northern Atolls). The centre is heavily dotted with coral patches (giri), some submerged and some awash. The concentration of giri is especially dense towards its SW quarter, close to Kandholhudhu Island (where there is the place most crowded with small reefs and shoals in the whole Maldives), but its narrower northern end is quite clear of reefs. The general depths of the lagoon are from 23 to 27 fathoms (42 to 49 m).

3. Fasdūtherē. Sandwiched between two atolls, the northern part of South Maalhosmadulhu forms a clearly delimited, roughly triangular, natural atoll without a distinctive name (Fasdūtherē merely means 'between five islands'). It is 22 km in length from east to west. It has 11 islands withe the only inhabited island being Kudarikilu Island on its SE corner just opposite Landaa-Giraavaru Island of Southern Maalhosmadulhu Atoll. Its lagoon becomes narrower towards the west and its average depth is 19 fathoms (35 m). It is separated from North Maalhosmadulhu by a deep channel (Moresby Channel in the Admiralty Chart) and from the southern part of South Maalhosmadulhu by the narrower Kuda Kanduolhi channel running from east to west.

4. Southern Maalhosmadulhu Atoll has many large farus on its western side. Its maximum length is 48 km. The inner lagoons (vilu) present an idyllic view. The depth of their waters is not more that a few meters, with perhaps a few coral heads awash. Its eastern fringe is a succession of separate, quite regular, oval reefs with some islands. The interior of the lagoon has also large faru towards its southern half. The average depth is from 24 to 27 fathoms (44 to 49 m).

5. Goidu or Goifulhafehendhu Atoll ( Horsburgh Atoll in the Admiralty Chart) is separated from South Maalhosmadulhu by a 10 km broad channel. This atoll is oval in shape and small, its greatest length being 15.5 km. It is composed of 7 islands, 3 of which are in habited. The inner lagoon has a depth of 17 to 20 fathoms (31 to 37 m); it has a sandy bottom mixed with mud and clay. Unlike the lagoons of most small atolls of the Maldives, this lagoon is free from coral heads in its centre.

Malé Atoll group

1. Kaashidhu Island, lies towards the eastern end of the channel to which it gives its name ('Kardiva Channel' in the Admiralty Chart). This island is surrounded by deep waters and there is generally heavy surf all around. It has an oval-shaped lagoon (vilu) with a narrow fringing reef on its NW side.

2. Gaafaru or Gahaafaru (Northern Reef) is a small island at the eastern end of a large elliptical reef that has proved disastrous to many vessels with the wrecks of Aracan (1873), SS Seagull (1879), Clan Alpine (1879), Erlangen (1894), Crusader (1905) and Lady Cristine (1974). 15 km long and 8.5 km wide Gaafaru reef is as much a separate atoll as Goidu or Rasdhu which are similar in structure and size. It is separated from Malé Atoll by a narrow but deep Gaafaru Kandu channel. Its lagoon has an average depth of 16 fathoms and has no coral patches or shoals in its centre.

3. North Malé Atoll is of irregular shape. It is 58 km long and contains about 50 islands (including the capital Malé). There are also sandbanks, coral patches, innumerable farus and submerged shoals (called "haa" in Dhivehi). The general depths of the interior are between 25 and 35 fathoms (46 to 64 m). The bottom is sandy. There are numerous passages on all sides. Seen from space it is considered one of the most beautiful atolls on the planet.

4. South Malé Atoll is separated from North Malé Atoll by a deep channel (Vaadhu Kandu). Oblong in shape, this atoll is 35 km in length. It contains 22 islands, all except for 5 are situated in its eastern fringes. Inside this atoll there are also many reefs and little coral patches which make navigation difficult. The general depths of the lagoon are from 25 to 32 fathoms (46 to 59 m), sandy bottom. South of the atoll lies the deep Fulidhoo Kandu.

Ari group

1. Toddu is a solitary round-shaped island located in deep waters at the western entrance of the Kardiva Channel. Its reef is steep and it lacks a lagoon.

2. Rasdhukuramathi Atoll ('Ross Atoll' in the Admiralty Chart) is a small atoll with an almost round lagoon. It is located almost 8 km from the NE point of Ari Atoll. The northern and western sides are one continuous barrier reef, and the eastern side is another. The 7 km wide lagoon has soundings from 15 to 20 fathoms (27 ot 37 m) and abounds in detached coral patches.

3. Ari Atoll is the second westernmost atoll of the Maldives, only after Maamakunudhoo Atoll. It is oblong in shape, 89 km in length by only 31 km in breadth. It contains some 50 islands, generally small, which lie mainly along its eastern fringe. Its features are intermediate between Maalhosmadulhu and North Malé atolls. Except for a small barrier reef in its southern end, it is shaped by a succession of large, separate oval reefs, like the large atolls in the North, with a clear rim of large faru to the east. In the interior the general soundings are 30 to 40 fathoms (55 to 73 m), with mud and sand. In places its lagoon contains small reef-patches, but it is generally dotted with many large coral reefs, some of which remain submerged even at low tide.

Felidhu Atoll group

1. Felidhu Atoll has a very irregular outline; it is surrounded by continuous barrier reefs, or by small patches with vilu separated by narrow passages. Felidhu Atoll has only 10 islands even though it is quite large. The Atoll’s western “horn” is devoid of islands and almost completely enclosed. Its eastern cape (Fottheyo Muli) is the easternmost geographical point of the Maldives. Both this cape and the westernmost point of this atoll (Fussaru) are dangerous for local navigation. Many ships plying along the route between Malé and the Southern Atolls, have been lost in these treacherous reefs. The distance between both points is 57 km. The inner lagoon is open with few reefs or shoals. Its general depth is of 40 fathoms (73 m); hard bottom of sand.

2. Vattaru is an egg-shaped reef or small atoll about 8.5 km in length. It has only one small uninhabited bushy islet close to its only entrance in the south. The depth of its inner lagoon is between 12 and 20 fathoms (22 to 37 m) and its bottom is sandy.

Mulaku Atoll

This is a very shut-in atoll with an open lagoon surrounded by barrier reefs which are remarkably straight and broad in its western fringe. Mulaku Atoll is 48 km long and contains 21 islands, which lie mostly on its SE quarter. The shoals inside the lagoon are generally smaller than in the Northern atolls. There are many coral patches and the depth of the water varies from 28 to 40 fathoms (51 to 73 m); sandy bottom.

Nilandhe Atoll group

This group is formed in reality by two atolls separated by a 6 km wide channel between them.

1. Northern Nilandhe Atoll is 29 km long. It forms a perfect semicircle on the east, but its western side is rather indented. There are not many islands on its fringes. In the interior of its lagoon there are four islands and several large farus, dry at low tide. The average depth of its lagoon is 25 to 35 fathoms (55 to 64 m). The atoll is seperated from Ari Atoll by the channel known as Ariadhoo Kandu.

2. Southern Nilandhe Atoll is larger than its northern neighbor, with a length of 38 km. It is seperated from its northern sister atoll by the narrow channel called the Dheburudheetheree Kandu. Its shape is slightly oval, with some barrier reefs that are quite straight in the eastern fringe. There are 21 islands, but only two or three are on its western side. The lagoon is comparatively open, with few, but relatively greater farus as well as a few small coral patches or shoals (giri); average depth 27 to 35 fathoms (49 to 64 m), muddy bottom.

Kolhumadulhu

The eastern and western rows of atolls that form Central Maldives end in this single atoll. It is mostly rimmed by barrier reefs which are topped by islands or deep pools (vilu). There are many islands along its southern boundary. Owing to its typical atoll shape, it differs in no respect from atolls in the Pacific Ocean, save for its greater size. The length of Kolhumadulhu Atoll is 51 km. The lagoon is comparatively open, although it is studded with numerous small coral patches or shoals which are awash at low tide. The general depth is from 32 to 42 fathoms (59 to 77 m) and it is mud-bottomed at the centre.

Haddhunmathi

File:Haddummati.jpg

Haddhummathi Atoll forms the southern limit of Central Maldives. Beyond the Huvadhu Kandu, the broadest channel between atolls in the Maldives, lie the Southern Atolls.

Haddhunmathi Atoll is regular in shape and 48 km in length. Excepting for the projection of the reef at its NE corner (Isdhū Muli), it closely resembles Kolhumadulhu. Its reefs are generally of little breadth, with no signs of vilu, except for its eastern fringes which are covered with islands that are quite large by Maldive standards. The lagoon is comparatively open, containing scattered shoal patches; the bottom is muddy and the average depth is from 30 to 34 fathoms (55 to 62 m).

Huvadu Kandu (Suvadiva Channel)

Further south Haddhummati in the middle of the vast emptiness of the Huvadu Channel there is a small bank known as Medutila (also called Derahaa). This place is the peak of a submarine mountain, and perhaps an atoll in the process of formation. This bank is very difficult to spot for at its shallowest point there is a depth of 6 fathoms (11 m). It looks like a paler blue patch surrounded by huge expanses of the deepest ocean. There, no island can be seen in the horizon for many dozens of miles.

Huvadhu Atoll

Huvdhoo atoll is the world larget atoll and also the largest of the Maldive atolls, it measures 79 km from north to south, embracing an area of about 2,900 square km. Huvadhu Atoll is fringed by a well-defined and almost continuous rim-reef. The exterior islands, formed in general of coral boulders on their seaward side (futtaru) and sand on the reef’s inner face (etherevaru), are string along the east, south and SW sides of the atoll. There are 30 sandy islands in the centre of its lagoon, more than any other atoll of the Maldives. The atoll's lagoon is open and very free from reef patches, although some precipitous shoals approach the surface. The lagoon bottom is covered with sand and has a maximum depth of 50 fathoms (91 m), being on average deeper than any other lagoon of the Maldive Atolls.

Fua Mulaku Island

Fuvammulah lies in the Middle of the Equatorial Channel or Addu Kandu. Its NE and SW sides are precipitous, with great depths close to the beach, but off its SE end a shelving bank extends for 3 km oceanwards, on which the surf breaks very high. The special distinguishing feature of this 5 km long island is its northern beach of polished coral gravel. Few of the beaches on its perimeter are sandy, most beaches are composed of shingle or polished flat rocks, which are called ‘hatha’ in the local language when they are large sized.

Addu Atoll

Addu Atoll seen from space. Note the continuous reef fringing Addu from the west and southwest.

This relatively small atoll marks the southern end of the Maldive archipelago. Addu Atoll is 21 km long and it is fringed by broad barrier reefs with large islands on its eastern and western sides. Its lagoon has no islands and is relatively open with few shoals in its centre, but having mazes of coral patches close to the NW and NE corners of its encircling reefs in 7 to 10 fathoms (13 to 18 m) of water. The general depths vary from 20 to 25 fathoms (37 to 46 m), with mud and sand at the bottom. The distance from Addu Atoll to the closest island in the Chagos Archipelago (Yeye Island, Peros Banhos Atoll) is about 520 km, with nothing but deep ocean in between them.

Channels

There are broad channels between the atolls. These were important for ancient mariners plying along the spice route trying to bypass the long atoll chains without harm. The most important ones were the Maliku Kandu‎, the Kardiva Channel and the Suvadiva Channel.‎

There are other types of channel in the atolls. One is the channel into the atoll's lagoon and the other is the passage on top of the reef into the vilu. These are very important for Maldivian sailors.

Island environment

The islands in the atolls of the Maldives rest on the shelf provided by the reefs. Many reefs have no islands at all. But all islands in the Maldives have an underlying coralline reef. Usually islands are flat and sandy. Often there is a rocky bottom made up of a coral rock conglomerate underneath the island proper. Some islands are long and sandy while others have a rounder shape. The round islands often are lower in the centre, sometimes having a muddy or marshy spot.

Islands may disappear when the currents on the reef change. Maldivians call this phenomenon of erosion giramun dhiyun. New islands also may appear, beginning as sandbanks or coral gravel heaps at another location of the reef (a phenomenon that is known among Maldivians as vodemun dhiyun). Therefore, in the Maldives, islands are constantly eroding and constantly being formed. Human action, in the form of jetties or the dredging of channels on the reef, may change the pattern of currents on the reef and accelerate erosion.

The atolls in Maldives are often separated from each other by vast expanses of the deepest ocean; but despite the great distances, the daily life of Maldivians in the individual inhabited islands shows very few differences all along the length of the atoll chain.

Except for the capital, Malé (pop. 90,000), the environment in most islands is dominated by practically the same small number of ingredients: trees of a few types, low houses with small yards, the waterside always close at hand and almost no dramatic variations in the landscape. The Maldives has about 200 inhabited islands. The typical population is about 300 inhabitants per island, distributed in about fifty households.

Neighboring island groups

The Maldive atolls are part of the long submerged mountain range that extends from the Laccadives, or Lakshadweep, in the north, to the Chagos in the south. Northern Maldivians used to visit often Maliku, Minicoy Island, before the 1960s when it was allowed for them to do so. In fact, Minicoy was called 'Avatteri Maliku', which means 'neighbor Maliku'. But even Northern Maldivians knew little about the Laccadive islands further north.

The Laccadives are different in structure from the Maldives. The most conspicuous fact is the absence of large atolls and the low density of reef and island structures. Most reefs have only one island on them.

In the south of Maldives the Chagos Archipelago is known as Hollhavai (Fōlhavahi in official Divehi). But even in these remote and strongly oceanic Southern Maldive atolls, knowledge about their neighboring island group is only vague and fragmentary. The Chagos group is a combination of different coralline structures. Unlike in the Maldives there is not a clearly discernible pattern of arrayed atolls, which makes the whole archipelago look somewhat chaotic.

However, one of the atolls of the Chagos, Peros Banhos, is very similar in structure to the typical Maldive atoll. Although it is rather small by Maldive standards, it is the largest emerged atoll in the Chagos. Peros Banhos is approximately as large as Northern Nilandhe Atoll.

Recent divisions

For administrative purposes, the country has been divided into twenty-one administrative divisions (20 administrative atolls and Malé city). Since these Administrative Divisions of the Maldives are called 'atolls', but are not always consisting of an atoll proper, they should not be confused with a natural atoll.

The introduction of code-letter names has been a source of much puzzlement and misunderstandings, especially among foreigners. Many people have come to think that the code-letter of the administrative atoll is its new name and that it has replaced its geographical name. Under such circumstances it is hard to know which is the correct name to use.

Aware of the extent of this problem, Maldivian expert Mr. Ibrahim Luthfee wrote a book on Maldivian geography before he died. With this book, which is unfortunately available only in Divehi, the late Mr. Luthfee tried to clear a number of misconceptions that carelessly researched tourist publications have generalized even among Maldivians. Much of this article has been translated and adapted from his posthumous work.

References

• Divehiraajjege Jōgrafīge Vanavaru. Muhammadu Ibrahim Lutfee. G.Sōsanī. Malé 1999.
• The Islands of Maldives. Hasan A. Maniku. Novelty. Male 1983.
• Changes in the Topography of the Maldives. Hasan A. Maniku. Novelty. Male 1990.
• Xavier Romero-Frias, The Maldive Islanders, A Study of the Popular Culture of an Ancient Ocean Kingdom. Barcelona 1999, ISBN 84 7254 801 5
• "The Formation of the Maldives". J. Stanley Gardiner. The Geographical Journal, Vol. 19, No. 3. Cambridge 1902.