The Ultimate Guide

ChibaDiving Guide

Chiba Prefecturein the southeast of the Kanto Region, is famous as the home of Narita Airport, the largest international airport in Japan. Much of Chiba is made up of the Boso Peninsula, sticking out into the Pacific Ocean, making it an ideal location for marine activities such as fishing, surfing, and of course, scuba diving. Easily accessible from Tokyo and boasting many fun dive sites, Chiba is an ideal diving destination.

Most of Chiba’s dive sites are located on the southern coast of the peninsula, where the Kuroshio Current arrivesbringing warm, clear, and nutrient-rich water from the south. Tokyo Bay and its abundant marine life lie on the west side of the peninsula, and on the east side the Kuroshio Current meets the Oyashio Current, creating a unique environment.

What you can see

Hundreds of banded houndsharks creating a tornado in Ito.

Banded houndsharks in Ito.
Banded houndsharks in Ito.
A red stingray hovers above the camera in Ito.
A red stingray hovers above the camera in Ito.
Beard grunts can be found in Ito and Nishikawana.
Beard grunts can be found in Ito and Nishikawana.
Beautiful nudibranchs everywhere!
Beautiful nudibranchs everywhere!

Season Calendar for Divers

East (Outer) Coast

KATSUURA

There are also dive sites near the underwater observatory, seen in the distance in the photo.
TThere are also dive sites near the underwater observatory, seen in the distance in the photo.

Katsuura boasts a shore dive site in Shimura Beach as well as two boat dive sites along with a selection of dive sites that only open seasonally.. Isomura is a popular boat dive site where many pelagic fish such as Japanese amberjack, yellowtail amberjack, and greater amberjack appear.

NAMEGAWA

Cavern diving at Kuroiwa.
Cavern diving at Kuroiwa.

Namegawa has a number of boat dive sites. There is Shinbama, with its assortment of marine life such as lumpfish, appearing from December to June, as well as an abundance of beautiful nudibranchs. Kuroiwaoffers cavern diving, where big fish like bullhead sharks and longtooth groupers can sometimes be found hiding under the overhang, schools of half-lined cardinal flit around, and shellfish line the cave.

South Coast

ITO

Surrounded by hundreds of sharks!
Surrounded by hundreds of sharks!

Possibly the most internationally well-known dive site in Chiba,divers from around the world come to meet the hundreds of banded houndsharks that live here, as well as the large populations of red stingray, bulgyhead wrasse, and longtooth grouper. The dive site at the heart of this popularity is Okimae-ne, a boat dive site located where the sharks gather. From January to early April, you can even enjoy birdwatching underwater, as Japanese cormorant dive into the ocean in search of prey.

NISHIKAWANA

Beard grunt at Ohne.
Beard grunt at Ohne.

Located at the very tip of the Boso Peninsula, Kuroshio Current hits this area directly, leading to a relatively high water temperature year-round and an abundance of marine life. Nishikawana offers a diverse assortment of dive sites, from cavern to sandy bottom. Ohne, one of these boat dive sites, offers the chance to observe many of the giant beard grunts Nishikawana is famous for. Schools of pelagic fish also start to appear around May, and if you’re lucky, you may be able to see a few hundred Japanese eagle rays!

BANDA

School of silver-stripe round herring.
School of silver-stripe round herring.

A quiet dive site beloved by French diver and fee diving world record holder Jacques Mayol,offering both shore dive sites and boat dive sites. Matsune features a bommie in which beautiful soft corals bloom, and at Karoune one can see huge school of Japanese sea perch, silver-stripe round herring, and many other fish .

HASAMA OCEAN PARK

Friendly bulgyhead wrasse called “Yoriko”.
Friendly bulgyhead wrasse called “Yoriko”.

One of the most unique dive sites in Japan, famous for its underwater shrine and the friendly bulgyhead wrasse that lives there. Sunfish and whale shark can also be seen here on occasion.

KENBUTSU

A little frogfish resting on a sponge.
A little frogfish resting on a sponge.

Kenbutsu has both shore dive site and boat dive sites. Oki-gyosho features an artificial fish reef in place for fishing, and the sea sponges that grow from it create the perfect home for small sea creatures such as frogfish. Triangle, a boat dive site, hosts a thriving population of several different kinds of corals, providing a great environment for small fish and juveniles.

OKINOSHIMA

The sun sets over the waters of Okinoshima.
The sun sets over the waters of Okinoshima.

Okinoshima is a small island connected to the peninsula by a sandbank and easily accessible by foot. It is surrounded by rock reef and is home to a bounty of marine life. Okino-chinsen offers wreck diving where you can see the creatures that live in the soft coral growing from the shipwreck. Okino Beach is a great dive site for macro photography, especially for nudibranch lovers.

Inner (West) Coast

KATSUYAMA

Katsuyama’s nudibranchs.
Katsuyama’s nudibranchs.

The Chiba dive site closest from Tokyo. There are dive sites around Ukishima, an uninhabited island only a small distance away from Katsuyama’s fishing port, and the two rock islands west of it. At Senju Drop, on the west of Ukishima, close to the Tokyo submarine canyon, divers can sometimes catch a glimpse of deep-sea fish.