Every year, toward the beginning of July, the waters of Zamami Island — so blue as to seem synthetic — are disturbed by a fleet of yachts. Almost 60 in number, the yachts cut elegant figures across the ocean, their hulls heeling and sails billowing as the prevailing south-westerlies drive them through Kerama Shoto National Park. They are in competition, each vying for position before reaching the finish line of the Zamami Yacht Race.

This is Japan's oldest continuous yacht race, and it has been held annually since 1977. The original iteration of the race took the boats all the way from Tokyo to Zamami, an arduous five- or six-day voyage of round-the-clock sailing. The race was soon cut to its current length, and now takes the form of a one-day epic, starting from the port of Ginowan on Okinawa and finishing just off the coast of Zamami.

With a good wind, the fastest yachts complete the race in just under four hours, starting shortly after 8 a.m. and finishing around midday to neatly coincide with lunch. The course — just over 40 kilometers in length — runs almost directly west from Ginowan, taking the boats past the smaller, uninhabited islands that dot the passage between Okinawa and Zamami.