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,
Gaafaru (Kaafu Atoll) Gaafaru (Kaafu Atoll) Gaafaru (Dhivehi: ގާފަރު) is one of the inhabited islands of Kaafu Atoll, the only island of the natural atoll known as Gaafaru. The island is north of the country's capital, Malé. Gahaafaru or Gaafaru (Northern Reef) is a large elliptical reef with only a small inhabited island at its eastern end. This reef has proved disastrous to many vessels. Gaafaru reef is as much a separate atoll as Goifulhafehendhu Atoll or Rasdhukuramathi Atoll which are similar in structure and size. It is separated from Kagi (the northern most island of North Malé Atoll) by a narrow but