Around a thousand species of fish on one small island, more than Okinawa, because the warm Kuroshio meets cold coastal water…Around a thousand species of fish on one small island, more than Okinawa, because the warm Kuroshio meets cold coastal water right here and both faunas overlap. Japanese ichthyologists have recorded dozens of first-for-Japan species on these reefs, and the water is famously clear. Kashiwajima is a fishing island of a few hundred people connected to Shikoku by a short bridge, and its reputation was made by divers and marine biologists rather than tourism. The Kuroshio running past it is the same current that keeps Japan's temperate coral alive. Anchorage: Anchor in the bay off Kashiwajima; the water is clear enough that boats appear to float in mid-air, which is what the island is known for. Hazards: Current on the outer points, and typhoon season Aug-Oct. Plus