Diving in Belize

Coral reefs, mostly mounds of underwater limestone, are the richest and most diverse and beautiful habitats in the sea. The lay of the local underwater landscape and the ocean currents make Belize proud owner of the largest coral reef in the Caribbean. This section will provide an overview of the marine environment and the types and locations of coral reefs to help you, the potential visitor to this underwater world, better understand what you will see and experience during your visit.

The Marine Enviroment

In the western Caribbean, surface currents tend in a Northerly direction which creates a thin Southerly counter current directly in front of the barrier reef and around the atolls of Belize.

Between the barrier reef and the mainland, the currents tend in a Southerly direction. The emptying of the many coastal rivers and the push of the Tradewinds creates a head of water which is funneled to the south and out southern edge of the reefs.

The strongest currents are generated by the tides. Though tidal range is small (seldom greater than 18 inches), the numerous cuts through the barrier reef can restrict the flow of water and cause strong local and temporal currents of up to 1.5 kts. These breaks in the barrier reef are habitats for large fish and rich coral growth.

The general sea floor profile of the coastal waters in Belize leads from the inland lagoons and beaches of the shoreline to the lagoon, barrier platform, barrier reef and wall and finally the coral atolls.

The inner lagoon consist mainly of sediments from river run off. Seagrass and hardy corals abound, and fishing at the river mouths is spectacular. Moving East, the lagoon abruptly rises to the barrier platform, a plateau of seagrass beds, coral sand islands and patch reefs. The barrier platform varies in width and composition from North to South. North of Belize City, the barrier platform is narrow, sometimes disappearing all together. South of Belize City, the platform widens to almost 6 miles. South of Blue Ground Range, the platform topography reaches its maximum complexity with a narrow outer platform; an area of drowned reefs, patch reefs and islands; and a deepening lagoon.

The furthest Southern island in this complex area of this barrier platform/lagoon mix is Laughing Bird Caye, a small island which perches atop a formation called a faroe. The Snake Cays and the Cayes of the Port Honduras Area are the furthest Southern islands in the inner lagoon. South of Gladden Spit, the outer platform narrows to about 1 mile, with wide passes through the barrier reef. The barrier platform ends in a hook shape at the Sapodilla Cays.

The barrier platform is bordered on the East by the barrier reef, a wall of coral which breaks the surface of the Caribbean Sea. The barrier reef crest slopes to the East to the edge of the continental shelf, where in numerous places vertical walls drop out of sight.