Yonaguni Island

Yonaguni is the westernmost inhabited island of Japan, part of the Yaeyama group in Okinawa Prefecture, and is known for distinctive coastal topography and underwater features. The island is small and sparsely populated compared with other Okinawan islands.

A main attraction is the underwater Yonaguni Monument, a series of submerged terraces and large rock faces frequented by divers. The island also offers rugged coastal scenery and local fishing ports that serve visiting dive boats.

The island has long been inhabited by Ryukyuan peoples and later came under the administrative control of modern Okinawa Prefecture. Its underwater formations were first widely publicized by divers in the late 20th century and since then have attracted scientific and recreational attention.

Yonaguni sits at the far western end of the Ryukyu (Nansei) island chain, close to the Taiwan coast, and is reached by air or ferry from other islands in Okinawa Prefecture.

• Diving access: Diving operations run from the island’s small harbors; many dive sites are suitable for experienced divers due to currents and depth.

What to See#

• Yonaguni Monument: A submerged rock formation off the island’s west coast featuring terraces, straight-edged steps and large flat surfaces that are a popular dive site and subject of debate over natural versus man-made origin.

Yonaguni is reached primarily by air from Ishigaki (New Ishigaki Airport). Flight time is about 30-40 minutes; airlines include Ryukyu Air Commuter and Japan Air Commuter (schedules vary seasonally). A slower alternative is the ferry from Ishigaki, which can take several hours and runs less frequently.

Once on the island, dive operators typically meet visitors at Yonaguni Port (Yonaguni-mura). There is a single main road; most dive shops will arrange local transfers to the harbor.

• Book a dive or snorkel with a Yonaguni-certified operator from Ishigaki - local captains know the currents and the best approach to the Monument.
• Plan for early-morning departures: winds typically pick up in the afternoon and can cancel dives.
• Bring a waterproof camera and a good torch; the stone faces and terraces of the submerged formations resolve best in oblique light.
• Ask your operator about tide and current schedules - some dives require brief drift segments and a surface pickup.