 The horseshoe-shaped reef discovered by Jacques-Yves Cousteau is known for its purple corals as well as diverse marine life ranging from small fish and harlequin shrimp to large pelagics like whale shark, manta ray, barracuda, and grouper.There are many stories about the naming of Richelieu Rock - many of which are demonstrably false.One such story is Richelieu Rock was discovered as a recreational scuba dive site by diving pioneer, Jacques-Yves Cousteau, with the help of local fishermen..