Osaki sits within the Kabira Area of Ishigaki and draws its character from shallow-to-moderate reef diving, with sites ranging from calm coral gardens and pinnacles to walls and drift dives. The Ribbon Eel and Orangestripe Triggerfish appear across nearly every site, while the Green Sea Turtle and Leaf Scorpionfish reward those who look carefully. Taketomi Hot Spring adds a geothermal curiosity found nowhere else in the area. Almost every site is boat-accessed, and the majority suit beginners.
Monthly water temperature across Osaki's sites, from satellite sea-surface data corrected for depth. The band shows the site-to-site spread.
Water stays warm throughout the year, peaking in summer when conditions are at their most settled and visibility is at its broadest. The cooler months remain comfortable for diving, though exposure increases and some drift sites like Yonara Channel see stronger currents. August draws the strongest ratings in the best-months data, reflecting calmer seas and optimal reef visibility.
17 operators
8 more sites to explore
Water temperature around Osaki ranges from about 23°C in February to 30°C in July, based on satellite sea-temperature data for its dive sites.
In the warm season (about 30°C) a rash guard or 3mm shorty is comfortable in Osaki; in the coldest months (about 23°C) step up to a 3mm full suit.
Fin maps 20 sites in Osaki (19 scuba diving sites and 8 snorkelling spots, with some suited to both).
The Ribbon Eel and Orangestripe Triggerfish are observed across the majority of sites and are among the most reliably encountered species. Green Sea Turtle sightings are common, and the Leaf Scorpionfish rewards patient observers on the reef. Whale Shark appearances are occasional rather than guaranteed, but have been recorded by divers in the area.
The majority of dive sites in Osaki are rated for beginners, including reef sites like Ukon Danchi, Nagura Coral Garden, and Three Rocks. These sites feature moderate depths and, in some cases, no current. Yonara Channel is the notable exception, rated as advanced due to stronger drift conditions.
All sites listed in Osaki are accessed by boat, so you will need to book through a local operator. There are many operators serving the area, including Prime Scuba Ishigaki, NOVA DIVE ISHIGAKI, and Phantom Island Tours, among others. Boat trips typically reach multiple sites in a single outing.
Coral reefs form the backbone of almost every site, but the area also offers drift dives at Panari Big Corner and Tokakinsone, walls and drop-offs at Kuroshima V-Drop, and cave sections at Kuroshima Nakamoto Cave and Oganzaki Lighthouse. Taketomi Hot Spring is a distinctive site where thermal water rises from the seabed, creating a noticeably warm zone around the spring.
