Why coral thrives here
The Kingdom's Red Sea and Gulf of Aqaba coastline runs for about 2,600 km. No rivers reach it, rain is scarce, tides barely shift, and the water is warm, clear and moderately saline under strong sun, conditions in which coral flourishes. Some Red Sea reefs date back about 7,000 years.
The sea holds about 1,000 species of fish and around 50 species of shark, among them the whale shark, which can grow to 12 m.
Shapes of the reef
The reefs take several forms. Some cluster along the shore and around islands, barrier reefs stand farther out, and ring-shaped reefs enclose shallow lagoons; others rise as coral heads or lie just beneath the surface, exposed at low tide. Off the northern coast, reefs reach up to about 50 nautical miles offshore.
They are densest at the mouth of the Gulf of Aqaba, between Tiran and Sanafir islands and the coast, then follow the northern shore to near al-Lith and continue around the islands to the southern end of the Saudi coast, past the Farasan Islands. Named reefs include Abu Shusha, al-Mismari and Mubarak.