Yakushima Island

Yakushima is best known for its ancient cedar forests and loggerhead sea turtle nesting beaches, but its surrounding waters hold an equally compelling underwater world. The island sits at the boundary between subtropical Kuroshio Current warmth and cooler Kyushu coastal water, generating nutrient upwelling that sustains dense kelp forests in the north and hard coral gardens in the south. Loggerhead and green turtles are encountered year-round on dive sites near their nesting beaches. Endemic reef fish appear alongside Kurosio-carried tropical visitors, and macro life — nudibranchs, pygmy seahorses, and frogfish — thrives on mixed substrate walls. The island's remoteness keeps dive sites uncrowded even in peak season.