The Diving in Japan Series -  Part 1 - An introduction to Japanese diving 

 Bonnie Waycott was born in the UK and lived in Japan for five years as a child, spending her school holidays snorkelling in the waters near her mother's hometown.  She learned to dive in 2010 and has been a regular visitor to Japan's underwater environment ever since.  Her blog Rising Bubbles (http://bonniewaycott.wordpress.com), a comprehensive guide to diving in Japan, was set up in 2011.  Here's her insider guide to a unique Japanese diving experience. 

Although you may not think it, Japan has some of the world's most varied dive sites; stretching from the icy waters off Hokkaido, the northernmost island, to the tropical coral reefs further south in Okinawa.  In 2011 the Ogasawara Islands, some 1,000km south from the country's main archipelago, were inscribed on UNESCO's World Heritage List.  Consisting of coral gardens, sand flats, ocean pinnacles, rock formations, ledges, caves and even blocks of ice, Japan's marine life is just as varied as its culture and landscape.

1.  Macrolife, Akasaki Beach, Kozushima, Tokyo

A little over three and a half hours away from Tokyo by fast boat, Kozushima, with its beautiful white sandy beaches, is an ideal summer destination for those who don't want to venture too far from the capital.  Divers can choose between a range of boat dives or a beach dive at Akasaki, an easy-going underwater experience with warm temperatures, great visibility and mellow currents.  Divers make their way over sheltered sandy and rocky terrain before spending most of the dive at depths of less than 10 meters.  The beach is home to an array of tiny life forms - baby sea slugs, tiny nudibranchs, starfish and crabs. Others such as bluespotted cornet fish and oriental butterfly fish stop by to graze off the rocks or just look around, no doubt used to the large number of divers that pass by.

2.  Ice Diving, Shiretoko Peninsula, Hokkaido

A harsh environment with huge amounts of snow and blizzards, icy cold winds and changeable conditions is no place for the faint of heart, and even less so for diving - or so you would think.  This is Hokkaido, Japan's northernmost island, in the midst of winter, but its pristine ocean and mountainous landscape are still enough to draw adventurous divers.  In February, frozen ice from the Sea of Okhotsk sets out on a journey.  Guided by the northerly winds, it breaks up and travels south to Hokkaido's northeastern Shiretoko Peninsula, marking the start of Japan's ice diving season.  Although it's possible to see a few fish, sea urchins, starfish and even a fascinating green shrimp over the rocky terrain, the real highlight are the sea angels or Clione.  The Clione have a transparent body, wings and cute ears.  They are sea slugs that are born swimming in the ocean and will continue to do so until they die.  If the spirit of adventure and challenging diving appeals, then ice diving is an absolute must. 

3.  Manta Rays, Ishigaki Island, Okinawa

In Japan they say that if you're after manta rays, Ishigaki Island is the place to be.  This quaint little spot is part of the southern islands of Okinawa (The Ryukyu Islands) and boasts of regular manta ray sightings.   Local dive school Umicoza takes regular photos of these giant creatures gracefully moving through the waters of a dive site called Manta Scramble, so-called because the mantas congregate, or rather scramble, to be cleaned and to feed off the blooming plankton.  Settling behind a large rock formation, the giant silhouettes in the distance are a surprise at first, but as you notice them get closer, one after another, it's impossible to take your eyes off them as they glide past, swooping in from all sides, content and happy as they hover above. 

4.  Star-shaped sand, Yoronto, Kagoshima

I almost wish that Yoronto (or Yoronjima or Yoron Island) could be a wonderful little secret.  Its beaches with soft white sand are like something from a picture postcard.  Tiny little pieces of coral from the surrounding reefs and deposits of dead plankton that look just like stars wash up as sand, and that's even before the diving begins.   Along the coast of Yoronto are stacks of great points with interesting coral structures and lots of fish.  There's even some limestone in some areas, forming a maze of tunnels and swim-throughs.  The star-shaped sand is found at every point as divers cruise past turtles, butterfly fish, pufferfish, red soldier fish and schools of long-fin batfish.  The huge variety of nudibranchs, eels and hundreds and other fish and invertebrates over the coral are enough to keep you busy.

5.  Turtles and Whales, Tokunoshima, Kagoshima

When diving off Tokunoshima Island, you may just spot a turtle or hear the sound of a whale if you keep your eyes and ears peeled.  In February whales fill the ocean with their cries, while turtles are often seen grazing off the rocks and drifting here and there.  One particular turtle, Yama-chan, has been living in the area for over ten years and is more than happy for divers to swim close to him and take photos.  Further out at sea are three rock islands that are home to large tuna, giant trevally and strong unpredictable currents, which means the site is not often visited.   If you have a playful nature and are up for adventure, then Tokunoshima is the place for you.

6.  Limestone, Rocks, Arches and Caves, Miyakojima, Okinawa

Miyakojima is well known for its limestone caves and arches that are winding and horizontal, opening out into wider sandy areas and small coral reefs where fish and soft corals pick up the rich nutrients drifting past in the mild currents.  The caves, coral formations, swim-throughs and tunnels are fascinating for a reason: porcupine fish, puffer fish, sea snakes and a host of other creatures seek shelter underneath table corals while black fin dart fish, shrimps, lion fish and angel fish have all made homes for themselves, adding much colour to the underwater environment.  Don't forget the rocks themselves -- they're a photographer's paradise, caked in an endless supply of macrolife.

7.  Dolphins and Squid, Miyakejima, Tokyo

Not to be confused with Miyakojima, the volcanic island of Miyakejima, formed by eruptions and lava flows, is a 6-hour overnight boat trip from Tokyo Bay.  Although one eruption in 2000 seriously damaged the underwater environment, it's still a fascinating place to explore.  It is best visited in May as the Tokyo area begins to warm up and the Kuroshio current brings higher sea temperatures and plenty of interesting marine life including the bigfin reef squid that come to spawn.  They deposit long white tubes filled with tiny eggs onto a cluster of tree branches, before swimming around keeping a close eye on things.  The nearby island of Mikurajima is popular for dolphins, and during May and June you can learn how to free dive and see them up close.

8.  Dive Training and Deep Bays, Osezaki Bay, Shizuoka

One reason Osezaki is such a popular dive spot is because of its close proximity to Tokyo.  It is also home to one of the deepest bays in Japan at around 2500 meters, with approximately 1000 kinds of fish. Some divers go there to practice their skills as a lot of areas here are simply well suited to dive training. Some concrete boulders at 5m are teeming with sea urchins at night, making them a great spot for buoyancy practice during a safety stop, while a collection of objects such as car tires and an old motorbike have been placed there deliberately and make an excellent site for search, rescue and navigation.  The night diving is surprisingly spectacular, with hundreds of moray eels, a baby octopus, shrimps and even huge curious sea bass that follow divers around.  For more advanced fun diving, other points outside the bay have excellent drop offs, guiding you to some whip coral at just over 20m.

9.  Fish TV, Oshima, Tokyo 

Because the island of Oshima is immediately south of Tokyo Bay, it's not thought of as a beautiful dive spot but there are some surprises to be found amidst the rocky beaches and interesting lava rock formations.  The underwater world here is extremely rocky but don't be put off by the lack of white sandy beaches and crystal clear seas.  At one dive site is a large rectangular arch called Fish TV, so-called because it often looks like it's filled with fish where divers can hover close by and watch from afar.  Some of the rocks are deep and house some impressive soft coral while others are huge and maze-like with walls covered in red anemones and clownfish.  Closer to the surface, don't forget to wear gloves and watch out for stinging hydroids. The seaweed, shellfish, spider crabs and box fish can be beautiful subjects for photos.

10.  The Yuzen, Hachijojima, Tokyo

Grazing in the distance off Hachijojima are the black and white Yuzen or Wrought Iron Butterfly Fish, taking their time hovering over the rocks and enjoying their latest meal of benthic algae and invertebrates on rocky reefs.  Knowing that they are endemic to Japan makes spotting them all the more special.  One of their most noticeable features is their metallic black and white colour and fins with a bright yellow tinge.  The Yuzen's home Hachijojima is 287km south of Tokyo and 12 hours on an overnight ferry.  It's a quaint little volcanic island with black sandy beaches, warm sea temperatures and a diverse marine life including turtles.  The beach dives are a world of crevices, cracks, walls and a fascinating world of colour containing angelfish, trumpet fish, golden spadefish and lionfish.  Take a fishing boat out into the open sea for even more diving adventures.