Vampire Squid Bioluminescence — Calauit Philippines

The deep waters around the Tubbataha Reef National Park in the Sulu Sea and the Calauit Island in Palawan host one of the most extraordinary bioluminescent marine encounters accessible to recreational divers — night dives that descend to the thermocline produce encounters with the vampire squid Vampyroteuthis infernalis, an ancient cephalopod that flashes blue-green bioluminescence from photophores covering its entire body when disturbed, creating a light display of ethereal alien beauty in the ocean's mesopelagic zone. The Philippines' extraordinary marine biodiversity — the centre of the Coral Triangle with more marine species per unit area than anywhere else on Earth — creates night dive environments of overwhelming species richness around every reef, with hundreds of nudibranchs, mantis shrimps, frogfish, and sleeping parrotfish in coral polyp mucus cocoons all visible by torch in water of remarkable clarity. The Tubbataha Reef's isolation in the Sulu Sea — accessible only by liveaboard from Puerto Princesa — creates an undisturbed reef ecosystem of exceptional health, and the combination of the world-class day diving, the bioluminescent night encounters, and the cetacean watching in the outer reef waters creates a Philippine marine experience of global significance. The bioluminescent plankton triggered by the bow wave of the liveaboard ship on flat-calm tropical nights — a comet-trail of cold blue light extending 100 metres behind the vessel — is itself a remarkable spectacle before the divers enter the water.