“Swept by a mixture of temperate and tropical currents, this great undersea sanctuary 60 miles southwest of Tokyo, Japan abounds with a richness and variety of marine life such as I have rarely encountered in more than 30 years of diving and marine research around the world.” Dr. Eugenie Clark, National Geographic

The offshore ecosystem found off Japan’s Izu Peninsula is unparalleled in the Indo Pacific, acclaimed by National Geographic and Ocean Realm as among the world’s richest and most diverse marine habitats. Millions of scuba divers have explored this rare combination of vivid marine life and spectacular volcanic undersea topography.

Mikomoto is not only famous for hammerhead sharks but for its entire marine species diversity and abundance. Only the Galapagos begins to compare. Diving conditions are also similar to the Galapagos with strong currents and unpredictable visibility. It is one of the most renowned drift diving areas in the world and conditions are usually very challenging. It is essential that divers who go to Mikomoto have adequate training and experience to control buoyancy, make safety stops and deploy surface safety alerts.

Although diving Izu’s renowned offshore island of Mikomoto is worth nearly any discomfort, open ocean passages to the island can push the limit so it is important to find the right dive operator.

Best Diving Destinations in Mikomoto

Kamene

World-renowned drift diving site offers experienced scuba divers extreme high-speed currents ripping through Mikomoto´s awesome undersea terrain composed of deep, colorful walls and steep ridges. Full of hammerheads and 1m long yellowtail jacks (seriola quinqueradiata). Located at the south end of Mikomoto, this diving area is affected by both northeast and southwest winds. 2-3 meter waves are common and currents are always present. Depths range from 15 to 45 meters with deeper dropoffs.

Aone

Renowned for extremely demanding, high-speed drift dives through spectacular undersea terrain. Located at the southwest tip of Mikomoto, this area is easily blown out by southwest winds. The current really rips on the ebb tide and the underwater terrain is deep and magnificently complex. Depths range from 7 to 45 meters with deeper dropoffs.

Enokuchi

This is one of the most beautiful scuba diving sites in Japan featuring huge rocks and ridges that descend sharply from Mikomoto to the ocean floor. You will be scrambling for your fish identification book if you can find your way to Kadone wall which starts at 20 meters and drops down to 45 meters. Check out the tiger sharks, the beautiful, huge, slow swimming tengudai (evistias acutirostris) which can reach a length of half a meter and migimaki (goniistius zebra) our favorite red-lipped stripped morwong. Mantas ride the warm Kuroshio this far north and have also been observed at this site. Located just west of a small bay that cuts into Mikomoto and is protected from northeast winds. Closes out in southwest winds and strong currents can develop on ebb tides.

Mitsune

Offers very mellow drift diving when the tide ebbs and is suitable for less experienced divers. Good place to observe tengudai, puffer and porcupine fish and schooling kampachi (seriola purpurascens), another jack similar to buri. Scuba divers often ride the slow ebbing current to Shirane. Located at the northwest tip of Mikomoto, pinnacles drop down to a relatively flat base at the 20-25 meter level with a 40-45 meter gorge in the middle. Current is usually slow and predictable. Closes out in both northeast and southwest winds.

Yakan

Another relatively flat and shallow area suitable for less experienced divers. Many excellent features here, sizable fish populations and a wide variety of other marine organisms. Good place to find octopus. Most scuba divers pass through this site drift diving from Mitsune or Shirane.Located at the north end of Mikomoto between Mitsune and Shirane, depths range from 7 to 25 meters and the site closes out in strong winds from the southwest and northeast.

Shirane

Excellent diving site for observing many varieties of bottom fish and other marine organisms. Small caves and crevices between the rocks and patches of sand shelter sleeping nekozame (heterodontus japonicus) catsharks, the equally beautiful and mysterious oose (orectolobus japonicus) carpet sharks and many varieties of sting rays (urolophus aurantiacus). Jacks and other schooling fish can be observed while diving at this site.

Located at the northeast tip of Mikomoto with a maximum depth of 20-23 meters. Northeast winds will close this area out.

Hashigone

Somewhat similar to Shirane but in close to Mikomoto, there are many pinnacle rocks which break the surface and provide excellent opportunities for exploration. Numerous marine organisms take shelter in rocky outcroppings and the marine species abundance is absolutely astonishing. Relatively calm area when the wind is from the west and southwest. Depth ranges from 7 meters close in to Mikomoto gradually descending to 25-26 meters to the east. Rolling waves and surge can make this area somewhat difficult and less experienced scuba divers need to be careful to avoid becoming caught in currents.

Dive Center

We went diving with H2O Eco Expeditions and reached the dive sites by H2O’s high-speed, 85kph jet boat. Operated by Japan Marine Conservation Center and H2O Eco Expeditions, the light alloy, computer-stabilized Eco Jet runs two trips per day out to Mikomoto Island.

Eco Jet is crewed by three professional divers certified to DAN PDS safety requirements which require training and certification in first aid specific to diver related injuries. All crew are accomplished divers certified as divemasters or instructors with a minimum of five years professional diving experience and 1,000 logged dives as dive guides.

Number of divers are limited to 18 to enhance onboard comfort and diving safety and H2O requires a minimum of 25-30 logged dives and advise divers to bring their own gear.

When to Visit Mikomoto

Water temperature at Mikomoto ranges from 14 degrees in the winter to 28 degrees in late summer and early autumn. Thermoclines are common and most divers use 5mm wetsuits even when the water is warm. Winter divers in Japan use drysuits to stay warm while enjoying visibility of up to 50 meters.

Getting to Mikomoto

H2O is the only boat diving operator situated in beautiful Shimoda, a picturesque seaside town of 30,000 people on Izu Peninsula just over a couple of hours from Tokyo, Japan. Rich in history and natural beauty, Shimoda attracts travelers from Japan and throughout the world who come to enjoy its beautiful white sand beaches, onsens, seafood restaurants, marine sports & vibrant nightlife.

H2O is located in Japan´s Shimoda Harbor and is within easy walking distance of Shimoda train station. Is it possible to go to Shimoda by train, dive Mikomoto and return to Tokyo on the same day. You can leave Tokyo by train at 8:30am and arrive well before the afternoon Eco Jet trip to Mikomoto. Day trippers usually leave Shimoda about 5:00pm and return home before 8:00pm.