Under The Okganzaki Lighthouse is a boat-access topography dive on Ishigaki's west coast, where lava ledges, arches and narrow cracks turn the reef into a natural maze. Light shafts through the holes and cave-like sections give the dive its shape, while schools of fish move along the reef edge. It is best in settled weather, especially on sunny mornings and around higher tide when the structure reads clearly. Expect guided boat logistics rather than any shore entry.