The town of Kushimoto is located on the southern curve of Wakayama Prefecture. It is surrounded by the ocean while nestled between mountains and the sea. Vessels from nearby ports bring fresh fish and seafood to traditional restaurants (izakaya).
Ships and shipwrecks also play a huge part in Kushimoto’s history, in particular the famous Ertugrul, dispatched from Turkey for a diplomatic mission in 1891. As it set sail for home, it was engulfed by a huge typhoon that broke the vessel into pieces, taking it straight to the bottom of the sea. This part of Japan may sometimes be treacherous, but it offers some of the best diving and snorkeling off Honshu. The reefs and rocky walls are home to Technicolor fish, macrolide and a comprehensive collection of sponges and soft coral that provide some fantastic photo opportunities. Every dive off Kushimoto is an experience in beauty and biodiversity.
The Black Tunnel
Because of its depth (36-40 meters), the Black Tunnel is only open to those with at least an Advanced Open Water certification. Although it’s not a long dive (mainly consisting of the descent and ascent), its underwater landscape is spectacular, interspersed with striking colorful sea fans and vivid sponges.
The descent is a feast for the eyes as sea goldies, knife fish and butterfly fish congregate close by, while the highlight is an arch between two huge rocks covered with soft coral that floats gently in the surge. Each side of the rocks’ vertical profiles drop precipitously into the deep blue, and every facet of the grand structure seems to be covered in an array of life.
Diving through the arch provides a grand entrance to a dive that becomes a kind of natural amphitheater, where a range of species seems to gather. Schools of half-lined cardinal fish coax you to swim closer, hovering at the entrance. Despite the deeper depth and colder waters, it’s tempting to stay down below longer, particularly as the jagged layers of rock are perfect hiding spots for crabs and shellfish.
Skirting back up toward the shallows, it’s clear growth is substantial as bits of hard coral compete for space, and fish seem to have populated much of the area. Don’t forget to look back as you leave and watch the arch light up as the sun shines through.
The glistening sunlight creates a captivating scene over this underwater landscape, making it all the more stunning. You may even encounter a common octopus or some longtooth groupers on the ascent.
Upon entering the water, it is clear Kaminoshima has much to offer. Its underwater environment provides a dramatic and diverse terrain, ample ambient light, plentiful marine life and stellar water clarity. With a maximum depth of about 20 meters, it’s an easy-going dive for everyone, with a fantastic array of life forms.
Descending to a rocky patch between 14 and 19 meters, closer inspection reveals a world of critters such as emperor shrimp and tiny crabs hiding in every hole or among the soft coral. Wire coral shrimp twist and coil, while pike blennies and black-bar chromis zip around and dart in and out of the nearest hiding places.
Nudibranchs comb the rocks too, and the ones here seem to have utilized every color in the spectrum to decorate their flamboyant bodies. With a broad palette of different color forms, they’re a key part of an unspoiled habitat for many species of coral and reef fish.
Growth on the rocks is also substantial, and the potential to find critters makes Kaminoshima a delight for macro photography fans. The site is one of the richest in terms of diversity and abundance of macrolife and provides the kind of diving that makes it easy to get lost for hours exploring every crack and crevice in search of the next subject.
The Kooza River
At first glance, the Kooza River may not seem the most enticing spot, and dipping your head into its fresh, clear and cold water comes as a bit of a shock.
In fact the river looks fairly unspectacular when you first enter, but beneath the surface lies a whole lot more; a carpet of stones, pebbles and small green plants leads to a series of huge rocks and boulders rich with life including a playful little salamander darting over the pebbles and curiously poking its head around. If you’ve wanted to try freshwater diving, you can’t go wrong here.
Thanks to the excellent visibility, you’re spoiled with a good few photo opportunities, and with a maximum depth of no more than five meters, you can spend a long time underwater and really explore the environs.
If you look around, an even more exciting encounter awaits—a giant salamander that calls the river its home. Many other interesting critters help you forget the cold water too.
Little shrimp peer from the crevices before drawing near and receding, while tiny fish huddle and hover over the pebbles. Keep an eye out for the pale chub, a common fish in Japan’s rivers and blessed with a beautiful mix of colors including pink and blue.
The barren landscape appears to offer very little, and there may be fewer fish species in the Kooza River than a full coral reef, but the fish here seem calmer and less afraid of divers.
Spending time here is like being in a different kind of aquarium with a mixture of fascinating underwater life. An added bonus is your gear and camera stay exceptionally clean; so no washing is required after your dive.
Nagizaki, Oshima Island
Oshima Island, which lies 1.8 kilometers from Kushimoto, is the largest island in Wakayama Prefecture. Nagizaki is among the island’s many dive sites. Here a huge rock formation rises out of the depths toward the surface. As you descend, the formation comes into focus, acting as an oasis for a range of inhabitants and schools of pelagic fish. A variety of soft coral is interspersed with red fans and yellow sponges, while a closer look reveals large and small nudibranchs, camouflaged scorpion fish and other critters hiding in every hole. The rocks support an incredible amount of marine life, from schools of fish to other species more difficult to find, such as tiny delicate anemone shrimps waiting and watching among the flowing tentacles of their home.
The site offers a multi-level dive with depths to more than 20 meters, and the bottom gradually begins to slope away to 30 meters or more. From about 25 meters, it’s possible to ascend slowly to explore the vertical walls that are home to pristine hard and soft coral and bursting with activity and texture, where fish and invertebrates hide away or graze on the encrusting life.
There are various nudibranchs with bright blue bodies and yellow markings, along with the odd predator including a few eels half-hidden within crevices and waiting to pounce on an unlucky passer-by.
Huge sea urchins can be found tucked away too, sometimes with their red urchin clingfish companions. Nagizaki is all about the little stuff hiding in and around the rocks. It’s a great location that keeps divers occupied searching for interesting species.
Getting There: JAL flights are available from Tokyo’s Haneda Airport to Nanki Shirahama Airport or Kansai International Airport. There is also a direct JR train from JR Shirahama Station to Kushimoto.
Getting Around: Hiring a car is a good option to explore the area. Taxis also run frequently from Kooza and Kushimoto stations.
When to Go: The warmest month of the year is August with an average temperature of around 27 C. January has the lowest average temperature at 7 C.
Water Temperature: Varies between 18 C and 29 C in the spring/summer and 16 C to 20 C in winter. A 5-mm wetsuit is best during the summer, however a 7-mm, or something even warmer such as a dry suit, works well in winter.
Accommodation: Dive Kooza near Kushimoto offers basic bunk bed accommodation for ¥2,000 a night (not including breakfast and dinner). Towels, showers, hairdryers and other amenities are available. Fun dives to the Black Tunnel, Kaminoshima and Kooza River are available here.
The dive operators in Kushimoto do not speak English and cannot answer English e-mail enquiries. If you don’t speak Japanese and want to dive Kushimoto, David Graham at Kansai Divers can provide information about travel arrangements and other details. David is based in Kobe and runs a group for divers in the Kansai area. E-mail at email@example.com.