The transect from the reef into the fore reef requires calm weather, a boat and knowledgable guide to go through the reef and approach it from the front side. If you wish to examine anything deeper than the very shallow fore reef, scuba gear and a dive master are required. Under no circumstances should one attempt to swim out through one of the passes in the reef to the fore reef without the presence of someone knowledgable about the waters. Currents in these passes can exceed the ability of even a powerful swimmer. Click here for information showing the main points of the Outer Reef Lagoon, San Pedro and South, and the main cuts through the reef east of the island.
Geologists refer to it as coralgal sand because most of the grains are coral and algal fragments.
If there is a sea wall, then the sand has been trucked in from excavations in the interior of the island and consists of varying mixtures of beach, shelf and lagoonal sands with all sorts of skeletal fragments. As you move out into the shallow water off store, there is abundant sea grass, mainly Thalassia , and many different types of algae trapping lime mud and sand. Many different organisms inhabit this environment, including sea worms and other burrowers such as the callianassid shrimp whose burrows are marked by mounds of clean sand. Small fish, anemones and crabs live among the grass and algae. Small foraminifera, bryozoa and worms encrust the grass.