The Oki Islands consist of four large inhabited islands and about 180 smaller uninhabited ones. Dogo Island (or Okinoshima) is the largest, followed by the Dozen Islands that consist of Nishinoshima, Chiburijima and Nakanoshima. Fishing, agriculture, delicious seafood (turban shell, rock oyster) and spectacular scenery are among the many aspects that make this part of Japan so unique.
The Oki Islands may not often appear on the dive destination radar, but that is precisely why being able to explore their underwater world is a special experience. It is also the first place in Japan where night diving began.
Volcanic structures, sponge-covered rocks, seaweed, carpets of sand—and that’s just scratching the surface.
WHERE TO DIVE
IGURI – Nishinoshima Island
After a 10-minute boat journey and a descent to about 16 meters, the adventure here begins. Iguri is a simple spot to navigate with two rocks stuck together while the dive boat’s anchor is carefully placed in the middle. At a depth of about 20 meters, the site does not appear to be the most exciting, with flat sandy areas and patches of seaweed growth here and there.
In fact, it’s a scene very typical of the Sea of Japan, but for those after macro life, it is full of little discoveries. Sponges and tiny nudibranchs cling to rocky formations that look as though they resemble ancient and ornate architecture, and even seem to vibrate with schools of fish and small swaying branches of seaweed.
Foraging through this leafy green seaweed reveals a plethora of nudibranchs that flaunt their colors, orange starfish and little crabs that frustrate your macro lens with their shyness as they scuttle away when you approach.
Those with a keen eye may also notice a slight movement of seaweed followed by a tiny fish or two nestled under the greenery.
The interaction with schools of chicken grunts that patrol the rocks, yellowfin amberjack that quickly swarm all around and damselfish that congregate together all make for wondrous diving.
With a maximum depth of about 16 to 20 meters, the ascent can be done very slowly alongside the rocks before it’s time for the journey back to the surface. Don’t forget to stop and look around at the schools of fish flitting around while the sunbeams pierce the water and dance above.
HOSHI-NO-KAMI-SHIMA – Nishinoshima Island
Although it takes 30 minutes by boat to reach this site, the journey is well worth it. Hoshi-no-kami-shima is a small, uninhabited island with a maximum depth of about 25 meters and most suited to advanced divers due to its current that can sometimes be fairly strong. The current brings with it a huge advantage—nutrients that sweep over the water column and bring the sea to life by enticing schools of fish that dine on plankton.
The walls of Hoshi-no-kami-shima plummet into the dark depths below and are known for their prolific life including a plethora of blennies, seaweed, sponges and tiny critters.
Beautiful soft corals seem to plume up from the seabed, clumping and sprouting alongside tube and barrel sponges that lie over the rocks, all offset by an ocean that can switch from a greenish tinge to a blue one when long rays of sunlight pierce through the surface.
The island is home to groups of chicken grunts and amberjack that drift slowly by and clouds of shimmering damselfish that flit in and out among the various soft corals and use them for their daytime hangout. There are some rocky patches worth taking time over, as you never know what might be hiding in the little holes and dark patches—the nooks and crannies seem to promise encounters with little critters and a range of smaller inhabitants.
OKI NO TATAMI – Okinoshima
The incredible dive sites around Okinoshima offer thrills of every shape and size from schools of large pelagic fish, strong currents and a range of seascapes to inspire divers’ awe. Oki no Tatami is literally one huge rock whose bottom lies over a carpet of white sand at 25 meters. It is most suited to divers who like macro life and enjoy taking time to explore their surroundings.
The current can sometimes be mild, but the best way to get the most out of Oki no Tatami is to simply circle around the huge rock itself. The shallower depths here are bathed in the sun as ripples of light skip across the hard rocky surface but, deeper down, the environment is a little darker and subdued with a lot less visibility. Covered in seaweed, the rock seems to have become an artificial reef-like structure in its own right.
The bonus is that it is home to a myriad of small fish such as schools of damselfish and several blennies with frog-like faces, curiously poking out their heads from their home in the rocks and taking divers’ minds off the slightly poor visibility.
With feathery tentacles above their eyes, some can look quite comical, staring intently as divers make their way past and perhaps no doubt secure in the thought their homes offer good protection. The site is a little simple and barren with almost no clue to the varied marine life but, on closer inspection, it is a very beautiful, classic Sea of Japan coast dive.
The Oki Islands are a cornucopia of marine delights and other fascinating experiences waiting to be discovered and enjoyed. I for one am really keen to return and continue my exploration of the Sea of Japan.
There are many diving spots around the Oki Islands, and the dive centers will choose places based on your skills and the weather/sea conditions. Here are a few of the highlights.