There swamps have formed behind high 15 and 20 foot sand dunes which have been thrown up by westerly hurricanes and retained by vegetation, mostly coconuts. This bank is slowly widening and extending westward into the lagoon. A cross section of the greater part of the Island would appear thus. Not to scale diagram: W OCEAN stunted vegetation scattered coconut bushes awash in reef LAGOON lagoon raises by westerly at high tide with westerly submarine sand already forming further beaches Coral ridges sea deposited vegetation raised CORAL ROCK. Swamps at below sea level stunted vegetation larger forest scrub E OCEAN