Atoll Atoll An atoll (, , , , or ), sometimes called a coral atoll, is a ring-shaped coral reef including a coral rim that encircles a lagoon partially or completely. There may be coral islands or cays on the rim. The coral of the atoll often sits atop the rim of an extinct seamount or volcano which has eroded or subsided partially beneath the water. The lagoon forms over the volcanic crater or caldera while the higher rim remains above water(s) or at shallow depths that permit the coral to grow and form the reefs. For the atoll to persist,
Raa Atoll the geographical and cultural point of view. However, they have become popular among tourists and foreigners in the Maldives who find them easier to pronounce than the true atoll names in Dhivehi, (save a few exceptions, like Ari Atoll)." Alifushi, located at the northern end of the atoll, is an island which has been traditionally famous for its skilled boatbuilding carpenters. It now houses shipyards. Hanikandu is the channel between Northern Maalhosmadulu Atoll and "Fasdhūtere" Atoll, beyond its southern border. This channel is also known as Moresby Channel in the honor of Robert Moresby, an almost forgotten captain and draughtsman,