"Atoll, a coral reef surrounding a pool of shallow water, usually called a lagoon. The atoll is formed by the building of a coral reef on a circular or nearly circular foundation. It is usually broken in one or more places so that the lagoon is connected with the surrounding waters." -Foster, 1921

Atoll

"Atoll, a coral reef surrounding a pool of shallow water, usually called a lagoon. The atoll is formed…

"represents a section of an island, from the ocean (o) to the lagoon (l). On the ocean side, from o to a, there is shallow water for some distance out; and where not too deep, the bottom is covered here and there with growing corals. Between a and b there is a platform of coral rock, mostly bare at low tide, but covered at high ... b to d is the wooded portion of the island. The whole width (is) from the beach (b) to the lagoon (c)." -Dana, 1880

Section of Coral Island of an Atoll

"represents a section of an island, from the ocean (o) to the lagoon (l). On the ocean side, from o…

Diagrammatic section of an off-shore bar and the barachois or lagoon enclosed by it.

Off-shore Bar

Diagrammatic section of an off-shore bar and the barachois or lagoon enclosed by it.

"Where the sea bottom has a very gentle slope, the waves break at some distance from the shore and the sand they carry is deposited, forming a barrier beach (B) along the line of greatest disturbance. The strip of water inclosed between the land and the barrier beach is called a lagoon (L)." -Dryer, 1901

Barrier Beach

"Where the sea bottom has a very gentle slope, the waves break at some distance from the shore and the…