Otsuki Reef

Otsuki Reef lies off the Otsuki Peninsula in western Kochi and forms a broad coral terrace at 8 to 18 metres backed by a gentle wall descending to 30 metres. Hard coral coverage here is among the highest on Shikoku's Pacific coast, supporting dense populations of reef fish including large grouper, Napoleon wrasse, and sweetlips. Manta rays visit the reef edge from June through October, using a recognised cleaning station at 12 metres where they hover motionless while small wrasse service them. The reef also receives scalloped hammerhead sightings on summer mornings when conditions permit early departure.