Discover One of Japan’s Hidden Diving Treasures
At the southern tip of Ehime Prefecture on the island of Shikoku lies Ainan — one of Japan’s best-kept diving secrets.

DIVE AINAN takes you into the pristine waters of the Uwa Sea, home to one of the first areas in Japan to be designated as a Marine Park. Ainan’s intricate ria coastline creates an extraordinary range of underwater habitats, and an impressive 849 species of fish have been recorded in these waters. 

Dive over spectacular coral reefs and colorful gardens of soft coral, explore dramatic underwater terrain and caves influenced by the Kuroshio Current, or slow down and search for tiny marine life hidden among the reefs. Seagrass meadows and Sargassum forests add yet another dimension to Ainan’s remarkably diverse underwater world. 

For underwater photographers, Ainan offers the best of both worlds. Macro enthusiasts can spend their dives searching for small and unusual subjects, while wide-angle photographers can capture coral landscapes, soft-coral gardens, schools of fish and dramatic underwater scenery. DIVE AINAN even organizes its own underwater photo contest, reflecting the shop’s strong connection with underwater photography. 

And there is another side to Ainan. Seasonal shark diving adds the possibility of exciting encounters with larger marine life, while recent dives have combined shark diving with sought-after macro subjects such as the Japanese pygmy seahorse—all within the same destination. 

DIVE AINAN is designed by divers, for divers. The operation has three dive boats, including a 37-passenger vessel introduced in 2024, with onboard toilets and hot-water showers. The waterfront facility provides spacious changing and relaxation areas, indoor and outdoor equipment-drying areas, hot showers, Wi-Fi and camera-friendly boat arrangements. AED and emergency oxygen are also available. 

But what makes DIVE AINAN special is not only the facilities or the marine life. It is the passion of a team that dives these waters continuously and wants every visitor to discover why this remote corner of Japan is worth the journey.

Come to Ainan for the diving.
Stay for the people.
And leave having discovered a side of underwater Japan that few international divers have experienced.