Kerama Islands National Park Diving

The Kerama Islands lie thirty-five kilometers west of Okinawa's main island, and beneath the surface, the archipelago's submerged topography creates a mosaic of drop-offs, caves, and coral gardens that rank among the Pacific's most concentrated dive ecosystems. The Japanese government designated the zone a national park in 2014, specifically to protect the coral reefs that had already made Kerama Blue a shorthand among divers for the water's signature cobalt transparency. The fifty-plus named dive sites distribute across the island group, but most operators concentrate on a dozen core locations accessible from Zamami and Tokashiki villages. The Unten Site off Zamami's northwest coast drops from five meters to thirty along a terrace carpeted in table corals, where green sea turtles forage on algae throughout the year. The Kannongawa Site on Tokashiki's southern flank presents a swim-through canyon system sculpted into limestone, its walls colonized by soft corals and visited by schools of bigeye trevally during summer months. Advanced divers target the Shimojishima Drop-Off, where the reef edge plunges past sixty meters and pelagic species—gray reef sharks, barracuda, occasional whale sharks—patrol the thermocline. Seasonal variation shapes both marine behavior and dive conditions. April through June delivers the clearest water and the last of the humpback whale migration, when mothers and calves rest in the shallows between Zamami and Aka Island. July and August bring the warmest water and the highest density of manta rays at cleaning stations near Kuba Island. September through November extends the calm-water window but introduces the risk of tropical storms, which can suspend boat operations for days. Winter diving from December through March remains possible, though sea temperatures drop to twenty-one degrees and visibility reduces slightly as plankton blooms increase. Marine encounters in Kerama Islands National Park diving are dictated by the reef's protected status and the archipelago's position along migratory corridors. The park's waters host five species of sea turtles, with green and hawksbill turtles present year-round at shallow foraging sites. The coral species count exceeds two hundred and fifty, dominated by Acropora staghorn formations and massive Porites colonies that survived the 1998 bleaching event. Night dives reveal bioluminescent plankton and hunting moray eels, while winter months occasionally bring pods of spinner dolphins into the bays. Operators run half-day and full-day charters from both main villages, with most itineraries covering two to three sites per trip. Certification requirements vary by site depth, and several operators offer guided snorkeling for non-divers at the turtle-frequented shallows. The national park imposes no entry fee for the marine zone, though all dive charters include environmental briefings and adhere to no-touch protocols for coral and marine life.