Japan's rare-macro reefs, protected coral bays and wild Shikoku headlands in one two-base road trip.
Overview
Kashiwajima and Tatsukushi sit on different sides of southwest Kochi's intricate coast. Kashiwajima, a small bridge-connected island in Otsuki, is famous for biodiverse coral reefs and slow macro-photography dives led by local shops. Across the road circuit, Tatsukushi has its own scuba and snorkeling operators, a four-zone marine park, guided sea kayaking and glass-bottom trips to Minokoshi Coast. Cape Ashizuri, Odo cliffs and the SATOUMI aquarium add worthwhile dry days. Plan separate shop departures and accommodation around Otsuki/Kashiwajima and Tosashimizu, not a single dive boat covering both. Summer brings warmer water but increased typhoon exposure; spring and autumn balance water activities and road touring. Kashiwajima swimming zones have enforceable local etiquette: use buoyed areas, avoid boat lanes and do not jump from bridges. Ashizuri Undersea Observatory ceased operations in September 2026.
JNTO and Kashiwajima operators describe rare fish, reef invertebrates and coral habitats, most rewarding with a trained guide and careful buoyancy.
Distinct Kashiwajima and Tatsukushi departure ports let divers compare local ecosystems without falsely advertising cross-coast boat service.
Quick shortlist before you jump into the full planning page.
Top species linked to approved dive spots in Kashiwajima and Southwest Kochi.
Named buoyed Kashiwajima beaches and Tatsukushi Marine Park zone 1 have source-backed surface access, subject to conditions.
Odo-yama, Tatsukushi/Minokoshi sandstone, SATOUMI aquarium and Cape Ashizuri offer activities beyond scuba.
1 linked spots
