Hahajima Hammerhead Point

Hahajima, the second-largest island in the Ogasawara group, is accessed by a smaller inter-island ferry from Chichijima and offers the best hammerhead shark diving in Japan. A seamount off the island's northern tip concentrates scalloped hammerheads (Sphyrna lewini) from June through September in aggregations that can reach 50 to 100 individuals on productive days. The cleaning station dynamics at 25 to 35 m draw the sharks in vertical columns; divers kneel on the sandy plateau and wait as the sharks spiral overhead. Oceanic blacktip sharks, silvertip sharks, and occasional tiger sharks add to the pelagic show. Outside hammerhead season the site produces large pelagic fish, resident sea turtles, and the dramatic deep wall that characterises Ogasawara's underwater topography.