Monthly Archives: August 2012

July and August 2012: Osezaki and Oshima, Japan

Saturday July 14th, Sunday July 15th, Saturday July 21st, Sunday July 22nd, Saturday August 4th and Sunday August 5th 2012

Divers often visit Osezaki and Oshima for fun and for training.  This year as part of my Advanced, I have spent a considerable amount of time at both.  One is a bay, the other an island, and each offer an excellent range of sites where various skills can be practiced and put to use.  Here’s a description of two of my dive group’s most visited destinations.

Osezaki faces out into Suruga Bay, which is small and open, but also one of the deepest bays in Japan at around 2500m with approximately 1000 kinds of fish.  The area crowded with divers in summer is a wide beach with several dive shops, restaurants and inns in the background.  Divers pick a spot, lay out picnic sheets and set up equipment before walking into the water.  The bay is sheltered and the sea is calm, making it ideal for first-time divers or training purposes.   It stays shallow, horizontal, pebbly and rocky for quite a stretch but when visibility is good, you can see seaweed stuck to the rocks and an array of fish darting around below.  After a while you come to a stretch of concrete boulders at around 5m, where there is a slight drop down to around 8m.  From then on, the bottom is sandy and muddy and spreads out towards the deeper depths.  With no more drop offs, you are free to swim out into the unknown.

The reason why people head to Osezaki to get certified or work on more Advanced techniques is that the bay has plenty of areas that are simply well suited for practicing particular skills.   The concrete boulders are home to millions of sea urchins, and an excellent place to practice buoyancy.  Located at 5m, it is there that divers must do their 3-min safety stop during an ascent so remaining horizontal and still is vital, even more so at night when millions of sea urchins are directly below.  Deeper sandy areas also require good buoyancy control as it can be easy to stir up the sand and reduce visibility in such parts.  The bay also houses a collection of objects, some linked together by ropes and others that have been put there such as car tires, a motorbike, a Winnie the Pooh object, mini shrine and bathtub.  This means that the bay’s underwater map is detailed and full of information for dive planning and navigation.  During a navigational dive or search and recovery practice, it’s good to keep an image of the map in mind and follow the ropes until arriving at a particular item but others objects that aren’t connected together can make things more challenging.  An SMB can be launched at any time, and various buoys are attached to the bottom by ropes, which is a good chance to practice an ascent and safety stop, but remaining horizontal and trying not to touch the rope or nearby rocks.    The deepest dives are around 30m – 40m, while night diving offers hundreds of moray eels, a baby octopus crawling along a rope, shrimps, and huge sea bass that can be curious and follow divers around.  For more advanced fun diving, places outside the bay such as Ipponmatsu and Sentan (the Point) are good recommendations.  These are not as sheltered, but have excellent deep drop offs that stretch down to some whip coral at a little over 20m.  Both are quite rocky and pebbly, but lifting up the odd rock here and there will reveal some interesting marine life.

Oshima is immediately south of Tokyo Bay and can be reached overnight from the Takeshiba port terminal.  The island doesn’t fill people with joy as a possible holiday destination and certainly isn’t glamorous but the diving is.  Akinohama is one of the main sites on the island.  A path from the car park leads to some gigantic rocks sticking out into the sea, where a giant stride entry takes you  into water that is 4-5m deep.  There can be a lot of swell at the surface or a slight current so it’s important to quickly head below, over a huge area of massive rocks covered in seaweed, shellfish, spider crabs, and box fish.  A good place for deep and night dives, the rocks continue on down to 20m – 40m and beyond, where you can find some incredible soft coral.   Nodahama, another dive site, is reasonably shallow and famous for its rock formations including Fish TV where fish gather at a big arch and divers can hover close by and watch.  After walking down to the beach from the car park carrying all equipment, entry into the water is by foot and can be difficult in rougher seas as you scramble over the rocks but there are ropes to hold and the area is shallow enough to sit down and put on fins and masks.  Once in the water, all it takes is to swim downwards along a slight slope, where the rocks get bigger and more wall-like, providing some good places for photography and observation.  It’s also possible to swim through Fish TV itself.  This route takes you out through more rocks and boulders with stinging hydroids (don’t forget gloves!) and some beautiful nudibranchs.  Keikai is another shallow dive spot but can have strong currents and navigation is particularly difficult due to a series of rocky ridges.  Divers put on their equipment at the car park and walk down to the beach, but the area is much more rocky and with the swell at the surface it is important to be ready and able to get into the water straight away.  The rocks become huge and maze-like almost immediately and down at around 10m-15m there are some beautiful parts including a wall covered in red anemones and clownfish.

See my entries of August 2011 (Oshima) and June 2012 (Osezaki) for practical information on how to get to these areas and the dive schools available.





July 2012: How to launch an SMB and a few other “Advanced” techniques, Yugawara Pool, Shizuoka, Japan

Saturday July 7th and Sunday July 8th 2012

The SMB, or Surface Marker Buoy, is a fascinating device to use and an integral part of being an Advanced diver.  Also known as a Safety Sausage, its role is to mark divers’ positions underwater so that boats know where the divers are, can pick them up, and show other boats that there are divers below.  The SMB comes with a spool which is locked with a small clip.  The whole thing can be fastened to a BC or kept in a BC pocket.  Deploying it is fun, but does take some practice.   To begin, unclip the SMB from your BC and unlock the spool.  The small clip is then attached back on your BC, and your next task is to unreel a little bit of the string around the spool.  Look around and make sure there is nothing above, below or around that could become entangled in the string.  Next, keep the spool and SMB in one hand, and inflate.  Depending on the type of SMB, this can be done in various ways – orally, using an alternate air source, or the actual mouthpiece.  The SMB needs to be at least half full in order to stay upright.  Inflate some more and let it rise to the surface, maintaining full control of the spool.  When it reaches above water, keep the string taut by adding some extra tension to make it stay upright, and ascend slowly.  Good buoyancy control is vital for a smooth launch.

Training for the Advanced certification, which I have decided to do slowly over the next several months, consists of many other techniques as well.  As usual, further buoyancy control is a must, but simply achieving that isn’t the end of things.  The checklist for my training says that a diver must never touch the bottom or float to the surface unless they want or need to, and must never disturb the marine life.  Good fin techniques are vital to staying horizontal and maintaining control as you swim along.  Part of the training includes practicing frog kicks, keeping your body and upper legs horizontal but bending your lower legs so the ends of your fins point upwards.  You then twist your ankle and lower leg at a right angle.

Because of limited space and being in a more controlled environment, buoyancy control, frog kicks and launching an SMB are all good skills to start off with in the pool.  During the weekend I used for the first time a type of BC consisting of a back plate and wing, and a long hose regulator.  The back plate is made of metal and attached to the wing using two big straps which then go around your tank.  Both must be fixed tightly to your body, and are great underwater as it feels as though the diver, back plate and wing are “as one.”  Compared to the conventional jacket-style BC, the back plate and wing make it much easier for the diver to stay horizontal as everything is fixed on the back, and less weights are needed around the waist as the metal plate is already considerably heavy.  With the long hose regulator, the regulator for breathing is placed on an extremely long hose as the name suggests, while the spare regulator is attached to a shorter hose and worn over the neck.  When sharing air in an emergency, the diver takes the long hose regulator out of the mouth, gives it to the out-of-air diver, and then uses the spare regulator.  This is another technique easily practiced in the pool.

Navigation is focused on once you begin training in the sea, but rather than being a separate task, it comes up in all dives.  An Advanced diver should always carry a compass, know how to read maps of dive sites and understand how to figure out the heading of each direction they will swim in.  Navigation is also a part of understanding standard dive procedures and being aware, knowing where you are going, any possible landmarks or hazard spots, and where the entry  and exit points are.  Deep diving however is different altogether.  Not only do you go deep (30-40m) but through simple calculations you are required to know your rock bottom pressure (minimum amount of air you need to get you and your buddy to the surface while you are both breathing from one tank in an emergency) and turnaround pressure (the lowest pressure at which you can be when you decide to head back to the ascent point).  Turnaround pressure is difficult to determine as it depends on how the dive goes, how long it takes to reach a destination and how long you want to spend there.  To calculate rock bottom pressure, you need to know how much air you usually consume per minute and this is a good calculation to practice regularly before figuring out your rock bottom pressure.

My checklist also states that in general, an Advanced diver must exhibit good buddy skills and awareness, keep an eye on his or her buddy and understand the conditions in the sea.  An Advanced diver must also evaluate dive logistics and environment, and have the confidence to decide whether to dive or pull out, using his or her skills, experience and readiness.  Above all, he or she must be fully confident to plan and execute dives with a dive buddy.

Being an Advanced diver changes your diving experiences in quite a big way.  Rather than following a guide or having others help out, you are expected to be a lot more independent.  Instead of simply doing the task you are given, like heading down to 30m and then coming back up again, an Advanced diver must have a greater input in his or her experiences underwater. As an Advanced diver, you’re expected to have a lot more say in your dives, and contribute to areas like planning, navigation, amount of air, depth and time spent underwater.  It’s important to have your say, make clear what you are thinking and feeling at the time, and why.  The Advanced has no deadline, and can be taken in a weekend or spread out over several weeks or months.  The reward is some great and fun adventures – night diving, wrecks, experiencing the deep and much more.

June 2012: The Joys of Navigation, Osezaki, Shizuoka, Japan

Saturday June 16th and Sunday June 17th 2012

All dives require a focus on safety, buoyancy, air, buddies and depth.  With poor visibility or currents to consider as well, the underwater environment really is THE place to get lost.   Of course there are no maps and divers are faced with a random terrain of rocks or coral gardens with nothing but blue as they stare ahead.  As training for my Advanced certification begins this summer, one important skill I need to learn is how to navigate.

Before that however, the first thing is to plan your dive.  Here are some things to consider:

  • Location – is it sandy, rocky or full of coral?  Are there wrecks or any small tunnels?
  • Water conditions – is there any current or poor visibility?
  • Divers’ navigational skill and level
  • Dive plan – are the divers planning to head north for 15-20mins, head west and go south?  Or will they move from point to point?  Is there anything in particular they want to see?
  • Map – draw a map on a slate or look at an actual one.  This helps the diver keep a mental picture of the site.  It’s also useful to mark the depths on various points, the entry point or location of the dive boat.   Plan a route.

Underwater compasses have a big lubber line (direction of travel line), a bezel (a movable ring full of numbers around the edge of the compass), a card (the white movable part that says N, S, E and W and full of numbers as well) and a window (a small one at the side of the compass to look through as you swim along).

With the help of some online information, here are some navigation techniques I found:  To navigate using the window, point the lubber line in the direction you want to go, and you will see a number in the window.  As long as the compass is level and the number stays there, you are going where you want.  Before a shore dive, point the compass in the direction you wish to ascend and remember the number in the window so when you are swimming back, you know you are going the right way if you see that particular number.

To navigate using the bezel, point the lubber line in the direction you want to go, and turn your bezel until the double triangle bit is right next to the N on the card.  As you swim, keep the compass flat and steady and make sure the lubber line is pointing towards your destination.  Then you should always see the N next to the double triangle. If not turn slightly until you do.  If the bezel is correctly placed, the number in the window will also be the same as the number at the end of the lubber line.

You and your buddy might decide to descend along an anchor line, and swim at 150 degrees (this number is called the heading) to reach a wreck.  Once you’re at the bottom, turn until you see 150 in the window, or turn your bezel so that 150 is at the far end of the lubber line and turn until the N is in the double triangle of the bezel.  To get back using the bezel, turn until the N is next to the single triangle.  Using the side window, note the number directly across from the direction you were heading in.  The number across from 150 is 330, so if you keep 330 in your window as you swim back, you should get back to that anchor line.

When navigating, it is easy to focus only on the compass and neglect your buddy and what is around you.  To make sure you keep an eye on your buddy and see a few things as well, look at the number in the window (for example 150), make a mental note and take in your surroundings.  It’s okay to swim a little to the left or right if you want to explore something or take photos.  Just remember that number 150 as you head to your destination.

My dive group train at Osezaki Bay in Shizuoka prefecture.  Located on the west side of the Izu Peninsula, the sheltered bay is C-shaped with a long beach full of dive schools, calm waters, a sandy bottom and plenty to see.  All of these make it very popular for dive training.  Further west of the bay are deeper areas full of boulders which you get to by loading up your dive gear on a cart, and heading out on foot.  The bay is particularly good for navigation as it is littered with objects – car tires, small statues, metal structures, a particularly huge concrete boulder, a motorbike, a boat, the list is endless.  Some are joined together by ropes, so to practice simple navigation, the best thing is to pick some objects you want to see and aim to reach them.

My buddy and I planned our dives using a map of the area complete with depth information.  For my first dive, we planned to head past a concrete boulder and follow a rope down to about 20m where we would find some car tires.  After exploring these we would ascend, stopping to look at a small shrine entrance before emerging at the surface.  With a picture of the map in my mind, I reached the car tires but got lost ascending and couldn’t find the shrine.   The deeper areas have no landmarks, so we discussed how deep we should go before turning left or right, and much air we should have when turning back.   I felt like more of a landmark person because I managed to pick out some rocks, whip coral and other features and successfully returned to our entry point, having remembered that we descended over a sandy slope that stood out among the rocks.  On Sunday, poor visibility at 20m completely threw me and I got quite lost but later things improved as I was more familiar with the site.   During the weekend we saw moray eels (including one being cleaned), blue banner fish, an incredible school of sardines (very rare to spot!), purple anemones, stone fish, wrasses, lion fish, sea urchins, catfish, nudibranchs and Moorish Idols.

Navigation sounds intimidating but it needn’t be.  Veering off course or finding something not part of the dive plan are opportunities to discover new sites or creatures, and trying to reach a destination is like a game and fun in itself.  It’s important to turn something that seems complicated into something that is fun, and with practice I’d like to learn more about the joys of navigation as well as the skill itself.

Practical information

  • To get to Osezaki, take the Shinkansen bullet train from either Tokyo or Shinagawa stations.  The early morning one leaves Shinagawa at around 7:34AM (destination Nagoya) and arrives at Mishima station around 8:19AM.  A one-way ticketwith no reservation costs 2,210yen.
  • It takes 12 mins to change trains at Mishima station.  Follow the signs to the Izu Hakone Tetsudo Line (Sunzu Line), destination Shuzenji.  The journey to Izu Nagaoka station is about 20mins and a one-way ticket is 320yen.  One train leaves at 8:31AM and arrives at 8:55AM.
  • At Izu Nagaoka station our dive shop accommodation (Osezaki Marine Service a pickup around 9:30AM.  It takes around 30mins to Osezaki Bay.
  • The dive shop is located right on the Bay with basic accommodation behind.  It has a big area selling books where people can leave bags, food and drink.  Outside are the tanks, while wetsuits, boots, masks etc for rental are behind the counter.  There are 3 toilets next door along with male showers.  Female showers are up some stairs into the building opposite.
  • Bring your own tea, coffee and snacks to have in between dives.  Hot water is available but cups must be borrowed from the restaurant next door.  Plenty of vending machines selling water, beer and soft drinks.
  • The shop takes a large area of the beach where customers can set up equipment.  You are responsible for everything – changing tanks, cleaning, and making sure everything is kept together.
  • To go to the deeper areas further west, take one of the carts parked nearby, load it with your equipment and head over on foot.
  • As I’d come with my group, there were no guides from the shop to accompany us on our dives, but no doubt this can be arranged for private bookings.
  • Lunch is available at the restaurant next door.  For around 1,000yen you can get basic curry, set meals of rice, miso soup and fish, or noodles.  Coffee is around 300yen.
  • All dives are shore dives, basic beach entry.
  • There are huge containers of water to wash wetsuits, BCs, regs, boots, masks and fins.  These can all be hanged on the rack next to the containers.  Compasses, dive computers, SMBs and cameras can be soaked in a smaller container next to the shop.
  • We stayed in basic accommodation next door to the shop.  One room can sleep at least 3-4 people on the floor.  All rooms are Japanese-style with tatami straw mats.  Dinner and breakfast not provided.  Our group usually has a BBQ.
  • There are no shops in the area so it’s a good idea to stock up on food and drink at the convenience stores close to Izu Nagaoka station.

June’s dives

Dive 1: Osezaki Bay: depth: 19.3m, dive time: 36mins, water temp: 22C, entry time: 11:42, exit time: 12:18, average depth 10.5m, used a 12L tank, 5kg weight belt, 5mm wetsuit and 2-3mm hood/vest, start pressure: 200 bar, end pressure: 65 bar, saw sea urchins, lion fish, moray eels, purple anemones, stone fish, scorpion fish and wrasses.

Dive 2: Sentan, The Point, Osezaki: depth: 21m, dive time: 41mins, water temp: 22C, entry time: 15:10, exit time: 15:51, average depth: 12.6m, used a 12L tank, 5kg weight belt, 5mm wetsuit and 2-3mm hood/vest, start pressure: 200bar, end pressure: 60 bar, saw moray eels, sardines and whip/soft coral.

Dive 3:  Osezaki Bay: depth: 22m, dive time: 34mins, water temp: 22C, entry time: 10:23, exit time: 10:57, average depth:12m, used a 12L tank, 5kg weight belt, 5mm wetsuit and 2-3mm hood/vest, start pressure: 200 bar, end pressure: 60 bar, saw a beautiful butterfly-like fish with wonderful big blue wings.

Dive 4:  Sentan, The Point, Osezaki: depth: 21.4m, dive time: 49mins, water temp: 22C, entry time: 13:08, exit time: 13:57, average depth: 12.2m, used a 12L tank, 5kg weight belt, 5mm wetsuit and 2-3mm hood/vest, start pressure: 200 bar, end pressure: 60 bar, saw nudibranchs, Moorish Idols, great colourful fish actually eating seaweed and the massive school of sardines once again.