Return to Magazine Index

There are gas masks and live ammunition such as these on the Nippo Maru, on most of the wrecks. Image by Neil Harris

Wreck Diving in Truk Lagoon

By Andrew Whitehead

Published in Dive Log Australasia
November 1998


The six-foot mako shark circled the tight group of divers at the final decompression stop on the anchor line. With their knives out, they alternately watched the shark, their dive computers, and the rapidly diminishing air supply in their pony bottles. The 80 cu ft drop tank hung temptingly under the boat, but no one was prepared to leave the safety of the group.  Fifty metres below, on the sandy bottom of Truk Lagoon, lay the old Japanese freighter, Nippo Maru, where the encounter had begun.

On board the Blue Lagoon dive boat, I was chatting with our driver, Doone, and we were unaware of the drama being enacted below.  We had one of our own!  The motion of the boat changed in the two-foot chop. 
Doone looked at the anchor rope and said, “The anchor has come loose!” 
There was no underwater buoy on the Nippo, so the hook anchor was used to hold the boat.  The weight of the divers on the rope had pulled it off the wreck.  The easterly wind blew the boat towards the reef off Dublon Island.  Doone started the starboard outboard and positioned the boat over the divers so that they could climb aboard after they were released from their decompression penalty.

Our trip leader, Neil Harris, was the first to surface after me and told me that a six-foot mako shark was bothering the divers.  They had first attracted its unwelcome attention near the bridge of the Nippo where he had been photographing the engine telegraph.  It reappeared while they were ascending the anchor line and proceeded to circle them.

Although this shark was not a large specimen, the mako is known for its unpredictable behavior so caution is required.  The shark did not go into the classic attack pattern. It may have been intimidated by the compact group of five strange, bubbling, beeping, aggressive creatures.  Paul  boarded next leaving Michael and Rod below with Chenney, our guide.  Michael surfaced and climbed aboard with his camera.  Rod arrived quite unconcerned, with Chenney last of all with his spear.


Every few years, Neil and Jenny Harris of Absolute Scuba ‘N’ Snorkeling organise a special dive trip to Truk Lagoon, in the state of Chuuk,  Federated States of Micronesia.  The lagoon is a large atoll where there are over forty wrecks of Japanese merchant ships that were sunk by American aircraft in February 1944.  We planned to dive on the best ten of these wrecks over a period of six days.  On this trip, our group of five old dive buddies flew from Brisbane to Osaka in Japan, then back to Guam, and finally to Chuuk.

We landed at 10am at Chuuk International Airport where the fun started.  In addition to the normal dive gear, we had pony bottles with separate regulators and Neil’s camera gear. Fortunately, we would only need polypropylene suits instead of bulky wet suits in the warm water. We eventually moved it into a big pile, explained to the customs people that it was all diving gear, and went through fairly smoothly.  Chenny from Blue Lagoon Dive Shop was waiting for us with some of the staff who helped us load our gear into the hotel van. Chenny agreed to personally guide us on all our dives to the best wrecks in the area.

As the boat circled over the San Francisco Maru on our third visit to that wreck, Chenny said quietly, “I should tell you that a local diver died here yesterday”. He had collapsed in his boat and died, presumably from an embolism. This unfortunate outcome is not surprising since local divers are not trained in decompression diving, and do not have adequate safety equipment. In the two previous dives on this wreck, Neil had noticed that there were very few mines in Hold 1 whereas it had been full in 1991.  Apparently, local divers retrieve the mines for use in fishing by explosives.  Three divers had been crippled by decompression sickness, and one had just paid the ultimate price for this dangerous occupation.

San Francisco Maru

The San Francisco Maru is an older style freighter, 117 metres long, lying upright at 60 metres.  It was used to carry munitions and they are still there! We glided down to the superstructure, then over the three little tanks, and around the bow gun, which is on a circular platform.  The others went over the side to the bottom to see the steamroller at over 60 metres and became fairly ‘narked’.  Rod and I went down into Hold 1 with the mines and detonators and found that there was a fair amount of empty space.  There is a narrow entrance to the lower hold but I returned to deck level because the top layer looked like it could fall in at any time.  I dived into Hold 2 and looked under the trucks.  I reached 53.9 metres at the bulkhead where there seemed to be an entrance to Hold 1, but I was not going in there! My computer showed deco of 4 minutes at 6 metres, 7 minutes in total.  With only 100 Bar in my main tank, it was time to go. 

Neil, Paul and Michael appeared as I ascended past the two tanks on the starboard side, and up past the bridge to the anchor line.  I waited until I reached 40 metres before using my old US Divers Calypso IV on the pony bottle. It had never been used before at that depth and it was a bit of a shock after using the Scubapro G250. There was only 50 bar left in the main tank which was not enough to make a safe ascent without the extra 24 cubic feet in the pony.  I made a slow ascent to 10 metres, stopped for 1 minute, slowly up to 6 metres, and then watched the computer for 4 minutes.  The next stage was 3 minutes at 5 metres, which emptied the pony.  I changed back to the main tank and did an extra 2 minutes at 3 metres before climbing aboard after a thrilling 26 minute dive.

Eten Island

We usually had lunch on Eten Island with some locals and a mangy cat for company. This consisted of a rough, slap-up Aussie lunch such as white sliced bread, sandwich spread, raw onion, corned beef and sliced cheese, all washed down with cola.  On one occasion, there was a group of pink-skinned Americans with one lad quite burnt.  There was no sign of Lycra sun shirts or polypropylene suits among them!

The island was transformed into an airstrip by the Japanese and has to its credit a Zero fighter, a Betty bomber, and an Emily flying boat in the waters nearby.  The island airstrip is now a coconut and banana plantation.  The dive boats tie up to the rock wall at the western end where there is an open picnic table and a wooded shelter with table and benches.  There is also a modern toilet nearby with a bucket to flush it.

Fujikawa Maru

It is a short trip from Eten Island to the Fujikawa Maru for an afternoon ‘shallow’ dive.  This freighter is 132 metres long and lies upright in 34 metres of water.  The ship was mainly used to transport aircraft. We descended over the big funnel and headed over the holds to the bow.  The 6-inch bow gun was taken from an old cruiser.  I followed Neil into Hold 1 where we found aircraft propeller blades and wings.  He took some photos of an outboard motor at the bottom of the hold at 37 metres.  I then followed Neil through the superstructure corridors and into the engine room.  There are catwalks, a long staircase and a six-cylinder diesel engine.  Neil went down into the aft holds while I swam along the deck to the stern and saw the matching cruiser gun. 

On our second visit to this wreck, Rod, Michael and I headed straight for Hold 2, which is in front of the superstructure.  We entered the hold between the hatch cover beams and found three Zeros without engines.  Michael took some photos of us in and around the fighters.  Rod sat in the cockpit of one of them for a photo opportunity.  We then headed up to the superstructure, which is now fairly open due to the deterioration of the steel and wooden structure in the relatively shallow water.

Truk is supposedly a dry state but we managed to buy the odd case of Budweiser at a bank-teller window. We also visited the supermarket to buy the next day’s lunch, five litre bottles of water, and a case of Cola.  On most evenings we went to the Truk Stop Hotel for dinner. There is a large patio, bar and jetty, so we sat outside and enjoyed a few Buds out in the cool night air.  During the time that we were there, we met the owner, three members of the International Olympic Committee, and two female American lawyers.

Shinkoku Maru

We had another wet ride way out to the west of Moen Island to the big fleet oil tanker, Shinkoku Maru, which sits upright in 40 metres of water.  Chenney volunteered to show us how to enter the ship through the torpedo hole on the aft port side.  I decided to wear my night-diving helmet with its twin torches each powered by 3 ‘AA’ batteries.  We descended over the superstructure and followed Chenney in his distinctive white shirt towards the stern.  Over the port side, we entered a jagged hole at 35.6 metres in single file.  A few twists and turns took us into the large engine room, with a huge diesel engine, catwalks and ladders.  After bumping my helmet (instead of my head) on odd bits of steel, and having everything illuminated wherever I looked, I decided to that it would be a good idea to wear the helmet on every dive!  We swam around the engine room like birds in a cage and exited through a hole in the roof.

Shotan Maru

On our first trip to the San Francisco Maru we ended up diving on the Shotan.  A strong easterly wind was blowing, so Doone cruised down the western coast of Dublon Island, through the old seaplane anchorage between Dublon and Eten Islands, and then straight into the chop to the San Francisco Maru.  Doone, who was driving the boat in the stern, caught most of the flying spray.  The luxury live-aboard Truk Aggressor II was anchored over the wreck site with active dive operations. 

Chenney suggested the Shotan Maru instead as it was on our list and only a little further east near tiny Fanamu Island.  We arrived at the new site already soaking wet in our polypropylene suits.  We bounced around in the 2-foot chop for some time before Chenny finally hooked onto the wreck. The Shotan Maru is an 87-metre freighter which is sitting in a valley with a sand hill on the starboard side.  The ship lies upright at about 50 metres.

We descended over the superstructure and headed down towards the stern gun. The gun is said to be a 3-inch and is covered in sponges.  My computer said depth 44.6 metres, NDC of 8 minutes!  I swam back along the aft deck where there is extensive bomb damage and the mast fallen over onto the sand hill. The hook anchor came adrift and went sailing past, so I chased it and caught it. The third crewman took it and attached it to the foremast.

Everyone was aboard except Michael who was still decompressing at three metres below the boat.  Then Chenny said that the hook had come off the wreck!  The boat was drifting away from Michael who was watching his computer as the deco requirement reduced, and his pony bottle slowly emptied.  Michael said later that he swam towards the boat, but the boat kept moving further away! 

“Can you see his bubbles?”  I asked.
Chenny pointed, Doone moved the boat back over the wreck and, sure enough, there was Michael clearly visible three metres down.  Finally he surfaced next to the boat, camera handed aboard, then Michael climbed the ladder looking very drained.
“Where have you been, Michael?  What have you been doing down there?”  we asked offhandedly.

Heian Maru

One day, we had morning tea at Eten Island, then headed up the western coast of Dublon Island to the Heian Maru.  This ship was a passenger and cargo liner, which was converted into a submarine depot ship.  It is the largest ship in the lagoon (155 metres long and 11,616 tons) and lies on its port side in 33 metres.

The water was green rather than blue, indicating that the visibility was down to about 15 metres.  Rod and I followed Neil and Paul’s air bubbles over the side near the bridge.  We swam towards the stern alongside the complex deck structure looking in various holes.  We finally reached the stern and swam around the counter to the port propeller, then up through the rudder to the starboard one.

We swam back a little higher and then along the promenade deck where we saw several long pipes.  Rod identified these as submarine periscopes.  We went deep into Hold 2 and found some torpedoes and warheads.  We continued on and found Neil and Paul near the bow.  They had been deep inside the ship and seen a great deal of charring caused by the uncontrolled fire, which started after the ship was strafed.  We found the name of the ship on the bow in English, where Chenny was waiting for us.

Jeep Island

Chenny suggested that we have lunch on a tiny island that was just visible to the east of our position.  It turned out to be a coral island called ‘Blue Lagoon Jeep Island’, which included a comfortable hut, covered eating area, toilet building, deck chairs and an outdoor table.  As I walked towards the table, a big, friendly puppy started eating the velcro straps on my boots and biting my legs.  He continued to bother us until I served him the remnants of the corned beef on a piece of bread under the table.  I then noticed that he had quite a few visible fleas on him!  Rod got into a hammock which was hung between two coconut trees.  The dog climbed in with him.  We watched all this from the picnic table with great amusement, while Paul took photos of Rod’s discomfort.

Rio de Janeiro Maru

After a two and a half-hour surface interval, we headed west to the Rio de Janeiro Maru, which lies off the east coast of Uman Island. This ship was a passenger liner, which was converted into a submarine depot ship, then to a transport.  It is 140 metres long and lies on its starboard side in 39 metres.

Michael, Rod and I descended near the bow, swam along the promenade deck, down through various doors and into Hold 4.  We swam out to the deck and followed it towards the stern.  In the aft hold, there where thousands of beer bottles.  Emerging from the hold, we found Neil and Paul at the stern gun.  We swam around the stern, which is very similar to the Heian Maru, and examined the rudder and the two propellers. 

Moen Island

On our last day, we went on a tour of Moen Island in an old van.  Up the hill behind the town, there are Japanese-made caves leading to a pre-WWI, British naval gun. We then drove along the northern shore to see the old lighthouse and communication centre. We jolted up a 4WD track to a large military-style building, which is now the Xavier High School.  At that elevation there were superb views all around, including the old Japanese Lighthouse, and a nice cool breeze.

On our way home we had time to spend the day in Osaka where we saw the Ring of Fire exhibit at the Osaka Aquarium.  The display occupied a four-storey building and included two whale sharks in an enormous tank.

Everyone agreed that it was a great trip.  Each dive was an incredible experience and without mishaps.  Safety was paramount with a high standard of training, good computers, and a pony bottle each.  An absolute adventure at one of the world’s greatest wreck sites!

Some Suggestions

During the dives I found my night-diving helmet very useful in order to avoid scrapes and bumps on odd bits of rusty steel.  For safe diving on these wrecks, a good dive computer and a pony bottle are essential. If you intend doing regular deep dives such as the Nippo, Aikoku, Shotan and San Francisco Maru, it would be a good idea to take tank bands so that you can use twin tanks with two regulators instead of your pony bottle on these dives.

Wrecks Explored

Aikoku Maru Stern gun, living areas, funnel and missing front half!
Fujikawa Maru Bow gun, aircraft parts, Zeros, superstructure, engine room, galley, stern gun.
Heian Maru Propellers, periscopes, torpedoes, ship’s name.
Kansho Maru Bow gun, engine room, steering gear, bomb damage to poop.
Nippo Maru Tank, shells, toppled funnel, Howitzers, paravanes, bottles.
Rio de Janeiro Maru Beer bottles, stern gun, propellers.
San Francisco Maru Bow gun, mines, trucks, tanks, steamroller, engine room, torpedo hole, cartridges, shells, torpedoes, depth charges.
Shinkoku Maru Hole in port side, engine room, bridge, officer’s bathroom.
Shotan Maru Stern gun, superstructure, funnel
Unkai Maru Engine room, bow gun, shoes, gas masks, bottles.

Useful references:
Hailstorm Over Truk Lagoon
, by Klaus Lindemann.
20 Principal Shipwrecks of Truk Lagoon
, sketches by Captain Lance Higgs of S.S. Thorfinn.
Truk Lagoon Wreck Divers Map
, by Dan E. Bailey.
Jane's Fighting Aircraft of World War II.

(Click here for pictures and more details about these wreck sites.)

Return to Magazine Index

Home News Scuba Diving Articles Author Contact Links