Tubbataha Reef is an atoll coral reef located in the Sulu Sea of the Philippines. Over 1000 species inhabit in the reef; many are already considered as endangered. Animal species found include manta rays, lionfish, sea turtles, clownfish, and sharks. The Tubbataha National Marine Park is open to live-aboard diving excursions between the months of April to June. It is in this period where the waves are most calm.