Hokkawa Dive Report

by Charles T. Whipple

Rudder-Scrapin' at Hokkawa

Hokkawa sits on the east coast of Japan's Izu Peninsula, a little less than three hours from the Akihabara district of Tokyo, where the Scuba Diving Club Manatees keeps its headquarters. When we gathered at 6:30 a.m., rain drizzled from overcast skies, even though the forecast had promised sun. A little rain never stopped the intrepid divers from Manatees.

Two vans pulled out of Akihabara at 7 a.m. sharp. By 10 we were parked outside Kenny's House in the hot-spring resort of Hokkawa. After a flurry of setting up cameras and climbing into wet and dry suits, the Manatees strolled the 100 meters or so down to the harbor and Kenny's waiting dive boat.

In moments the 22-foot boat's twin Yamaha outboards had us up on a plane, headed for the Rudder-Scraper — Kajikaki in Japanese — a cluster of rocks that come so close to the surface at low tide that local fishermen sometimes scrape their rudders on them. The site has three permanent buoys, so the captain can pick the one that suits the wind and current. We tied up to the buoy on the southeast corner of the rocks.

A Cold-Water Welcome

One of the Manatees had never dived in Japan before. She had earned her open-water certification in Guam, and all 43 of her dives had been in those lukewarm tropical waters. Needless to say, her backroll entry brought a gasp of surprise. The water over Rudder-Scraper rocks was only 18 degrees Celsius — about 65 Fahrenheit. Still, in 6.5 mm wetsuits, it wasn't too bad.

We descended into typical Japanese spring water: full of nutrients and vibrant with life. Everything was moving. Spiral worms and other hydrozoans were out in force. Nudibranchs courted in slow motion. And cardinalfish — it felt like hundreds of thousands of them — swam round and round the tallest rock. Just as we turned to leave, one Manatee noticed a flounder on the bottom. We swooped down for a closer look, but it had other plans. Suddenly it lurched up into the cloud of cardinalfish, snapping this way and darting that, trying to catch a meal. The cardinalfish were the nimbler of the two, and while we watched, the hungry flounder dropped back to the sand to sulk and, perhaps, do a little image training.

We may have seen more lifeforms in 40 minutes at Rudder-Scraper rocks than our Guam diver had in all 43 of her dives there — well, maybe not quite.

Back aboard, she could not stop exulting about the sheer abundance of Japanese ocean life: soft coral, rhinoceros shrimp, nudibranchs, scorpionfish, hydrozoans, sea fans, groupers, sea bream, rock lobsters — you name it. Each scorpionfish braced itself with a fin on either side of the sponge it hid in; under the strobe the colors blazed, but in natural light the fish all but vanished into the background.

Why I Keep Coming Back

I've dived dozens of sites in Japan, many of them only a couple of hours' drive from Tokyo, and many of them more times than I can count. Each visit turns up something new. The sites change markedly with the seasons, so you get to watch the entire lifecycle of many species. In the Bahamas, divers go into a frenzy over spotting a single moray. In Japan, it's unusual when you don't see one. For my money, Japan is still one of the best-kept secrets in the diving world.

The Onsen Finish

Back to Hokkawa. Kenny's boat docks at the quay, and the Manatees shift their gear over to fresh tanks. We hustle back to Kenny's House, because there's a naturally hot pool you can climb into wetsuit and all. As the hot water draws the chill out of your bones, you start peeling off gear, one piece at a time. One of Kenny's people comes to take your lunch order. You climb out warm clear through, hang your gear up, and by the time you've wandered over to the tables in front of the shop, lunch is served — hot, but not too filling, because you still have one more dive on Rudder-Scraper rocks to go.

Plan your dive

Hokkawa is a small, low-key dive village on the east coast of the Izu region, a comfortable day trip from the Tokyo area and a favorite of Kanto divers for its complex underwater terrain, healthy soft-coral gardens, and rich macro life. It's also a hot-spring (onsen) town, which makes the post-dive warm-up part of the appeal.

Best season: Diveable year-round. Summer through early autumn (roughly July–October) brings the warmest water and biggest fish life; winter and early spring trade warmth for the year's clearest visibility.
Water temperature: Around 15°C in the coldest months (February–March) and up to 26–27°C at the late-summer peak, when the warm Kuroshio current pushes north. A 6.5 mm wetsuit suits the warmer half of the year; many divers go dry in winter and spring.
Visibility: Variable — nutrient-rich spring water can be green but teeming with life, while cold, clear winter days offer the best long-range visibility.
Level: Sites suit a range of experience; conditions and currents vary, so newer divers should go with a local guide and watch for cooler water than tropical visitors expect.
Getting there: From Tokyo, take the Shinkansen to Atami (about 45 minutes), then change to the local JR Itō line down the east Izu coast; from Itō it's a short hop on toward the Hokkawa area. Many Tokyo dive clubs run vans straight to the village, roughly a three-hour drive.

For more on the wider region and other Japanese dive destinations, see our Izu guide and the interactive dive maps.

Charles Whipple was a writer who lived in Japan for more than 20 years. An avid diver, he contributed diving articles to Australian, New Zealand, Japanese, and American magazines and was always glad to help fellow divers get acquainted with Japan.

Mr. Charles T. Whipple passed away in 2019. Rest in peace. Copyright in this article and its photographs was reserved to Charles Whipple and now belongs to the person who inherited it.