These giant marine animals appeared about 150 million years ago. Manta rays can be up to 7 m in size with brachial slits located on the belly and oversized pectoral fins welded to their head enabling movement. Anau is a classic manta ray "swarm site" among the French Polynesia islands. They usually avoid contact with humans, but not in this spot. You can safely swim next to them. However, please do not touch them. In this lagoon which is famous as a “manta ray channel” there are usually over 30 of these huge devils simultaneously.
May through December is the best time for diving and swimming with manta rays.