The Kerama Islands
The islands of "Kerama blue"
Go because they hold some of the most beautiful and accessible sea in Japan — a cluster of small islands famed for water so vivid it has its own name, "Kerama blue," and all just a short boat ride from Naha.
Come for world-class snorkelling and diving over vibrant coral; for the chance to see sea turtles gliding beside you and, in winter, migrating humpback whales offshore; and for near-empty white beaches on tiny islands — an easy day trip or overnight escape from the Okinawan capital. Now a national park.
Just off the coast of the main Okinawan island lies a small cluster of islands with an outsized reputation: the Kerama Islands, whose waters are so extraordinarily clear and blue that they've given a colour to the language — "Kerama blue." Designated a national park to protect their reefs and turtles, these little islands — chiefly Zamami and Aka — offer some of the best and most accessible marine experiences in Japan: snorkelling with sea turtles, diving over healthy coral, and swimming from soft white beaches, all within an easy boat ride of Naha. For anyone based in the capital, they're the perfect glimpse of island paradise.
A little background
The Kerama Islands were long a quiet fishing and farming community within the Ryūkyū world, and saw fierce fighting in the Second World War. In modern times their pristine reefs and remarkable water made them a diving and snorkelling destination, and in 2014 the surrounding sea and islands were designated the Kerama Shotō National Park to protect the coral and the sea turtles and whales that frequent these waters. The main inhabited islands are Zamami and Aka, with tiny Tokashiki the largest.
What to see
The beaches & the "Kerama blue." Beaches like Furuzamami on Zamami and Nishibama on Aka offer soft sand and that famous luminous water — often near-empty, especially on a day trip's quieter edges.
Snorkelling with turtles. The Keramas are among the best places in Japan to snorkel alongside wild green sea turtles, which feed in the shallow bays.
Diving. Healthy coral and clear water make these islands a premier dive destination, with reefs, drop-offs and abundant marine life.
Whale watching. In winter (roughly January–March), humpback whales migrate through Kerama waters, and boat tours run from the islands and Naha to see them.
How to get there
The Keramas are reached by boat from Naha's Tomari Port: a fast ferry to Zamami or Aka takes around 50 minutes, a slower car ferry about 2 hours (Tokashiki is a similar short hop). This makes them very doable as a day trip, though an overnight in a small island guesthouse lets you enjoy the beaches once the day boats have gone. Book ferries ahead in peak season.
When to go & practical notes
April–June and October–November bring warm, clear water and calmer seas; summer is peak but hot and typhoon-prone; winter is cooler but the season for whale watching. As a national park, the reefs are protected — use reef-safe sunscreen, don't touch or stand on coral, and keep a respectful distance from turtles and whales. Facilities on the small islands are limited, so bring what you need for the day, and book ahead if staying over.