Hoki Maru

A Prize of War

Text & Images by Mike Gerken

©All Rights Reserved.

(As seen published on scubaboard.com on April 28, 2012)

HMS Hauraki Painting A painting of the M/V Hauraki by J.E. Hobbs. Courtesy of the Wellington Maritime Museum.

            Warplanes with guns blazing hurtle through the skies over Truk Lagoon; many fall earthwards with telltale flames and smoke emanating from the spiraling wreckage. One by one, Japanese pilots, outgunned and outmanned, desperate to defend their stronghold from marauding enemy planes, are shot out of the sky by Hellcat fighter planes. Avenger torpedo bombers glide low over the surface of the lagoon and aim their sites upon a hapless ship sitting at anchor. Torpedoes are released and slam in to the 7,000-ton vessel, splitting the steel open as if it were made of foil. A rush of seawater pours through the ruptured hull, flooding the compartments within. Helldiver dive-bombers adding to the melee; plummet from altitude and un-leash the 1000-pound bombs strapped to their bellies. The projectiles pierce the deck and ignite a stockpile of fuel and ammunition within the holds. Like a sleeping volcano, the entire forward section of the vessel erupts violently, sealing the fate of a once proud vessel. Debris is launched high in to the air while dense black smoke envelops the ship. Many of the crew perish in a ball of fire. When the smoke clears, the ship is gone. Another hapless victim of ‘Operation Hailstone’, the United States carrier based air raid launched on February 17, 1944 at the height of the war in the Pacific.


  US Planes Over Truk            Such was the fate of the Japanese merchant ship, the Hoki Maru; the result of the wrath of a nation scorned and relentlessly seeking retribution for the treachery suffered at Pearl Harbor. United States air forces would sink more than four-dozen Japanese ships and destroy 250 planes during the two-day air strike. The victory at Truk Lagoon was incremental in stemming the rampant and unbridled advancement of the Japanese Empire across the Pacific and East Asia during World War II.


            The event unknowingly created one of the world’s greatest wreck diving locations in modern times. Sport divers the world over travel from afar to visit this small Pacific island nation to see first hand the result of this devastating attack. The ‘Hoki Maru’ being only one wreck site of dozens to explore.


             The Hoki Maru was not christened as such. Built in Scotland for the Union Steamship Corporation of New Zealand in 1921, the 450-foot ship rolled off the slipway by the name of the M/V Hauraki. Her state of the art diesel engines would propel the ship on service runs between North America and New Zealand until 1942. The British requisitioned her for wartime usage at that time.


Truk Lagoon Attack

            Sailing from Sydney, Australia, the Hauraki would be intercepted by Japanese merchant raiders, Aikoku and Hokuko Maru and taken back to Japan via Singapore as a prize of war. Many of the Australian and New Zealand crew were sent off to prison camps where five died as a result of the horrid treatment received there. The Hauraki engineers, however, were forced to stay on board in order to facilitate the running of the diesel engines that Japanese engineers knew not how to operate. Determined to not let their ship become an asset for Japan, the bold crew of the Hauraki set out to sabotage her at every turn.


            The men were thorough at disabling their vessel by tossing tools and spare parts overboard and allowing the engines to fall in to disrepair. So effective was their job, that by time the Hauraki arrived in Japan, the ship was in such ruin it would take 18 months of refitting to return her to service. All this was accomplished without the knowledge of their Japanese captors.


            In December of 1943, the Hauraki was renamed the Hoki Maru and ready for service, albeit a short service at that.  She would arrive in Truk Lagoon sometime in February of 1944 where she met her final demise at the hands of US planes.


            Truk Lagoon is known today as the state of Chuuk. The ‘Hoki’ is one of the premier dive sites there with liveaboard and land based dive operators both making regular trips to dive her. She came to rest on the lagoon floor in approximately 150 feet of water. More than 200 feet of the forward section of the ship is splayed open like a peeled banana due to the violent explosion. However, the stern section is still remarkably intact and sitting upright. It is the artifacts found within the aft cargo holds that are the main attraction of this dive.

HMS Hauraki

The M/V Hauraki prior to capture by the Japanese.

            I first saw the Hoki Maru in 2003 while working on the liveaboard, Truk Aggressor II and later with another liveaboard, the Truk Odyssey. By the time I left in July 2008, I was fortunate to log more than 2,000 dives in Chuuk with more than 150 on the Hoki Maru alone. The ‘Hoki’ sits in an area of the lagoon that receives a fresh supply of blue water from outside the barrier reef offering exceptional visibility that can exceed 100 feet. Water temperatures in the low eighties and mild currents are the norm.


            Upon diving the ‘Hoki’, I follow the vertical mast down that juts up to 70’ from the wreck below. Once to the bottom, I find myself at a depth of 115 feet and forward of hold number five, the furthest cargo hold aft. I make my way aft and hover over the cargo hold, I look down in to the darkness between the hatch cover beams that stretch across the opening. These beams once supported the wooden floors that have long since rotted away. Perched atop the beams on the middle level is the remains of a bulldozer whose massive weight pressing down for 65 years has caused the steel beams to bend and twist like a pretzel. Each time I descend down in to this hold, I make a point not to swim beneath it. Even though the dozer has been sitting there peacefully for decades, you never know if that moment you happen to be underneath it, will be the moment ten tons of machinery decides to crash down upon you. It is better to be safe than sorry.

Truk Trucks II

            I arrive at the mid level of the cargo hold and my depth gauge reads 135’ of seawater. I shine my dive light towards the stern and parked neatly underneath the overhang stand three vintage pick-up trucks facing the aft bulkhead. There are two others off to my right. Although showing signs of age, the bodies of the 1940’s era vehicles are in surprising good condition. I swim around the front in the tight space between the trucks and the bulkhead and snap a few photos. Not stirring the thick layer of silt that has accumulated on the floor makes the effort all the more difficult.


            As I turn and begin to swim up the starboard side of the cargo hold, I now see a tractor complete with steering wheel and seat. Oddly, the treads on the tires are mounted backwards. This may be because the tractor was to do more pulling than pushing, or simply, it was an error.


           After inspecting the tractor, I begin to head forward while passing under the well lit center section of the cargo hold. As I swim to the opposite side the sunlight begins to fade to blackness again. I shine my light in to the dark reaches of the room and see the backs of another three large dump trucks.  Like the other cargo in this hold, these trucks are mostly intact with the exception of all the glass windows that are busted out. The bumpers are practically touching the forward bulkhead of the compartment so I swim in the tight spaces over their hoods towards the port side of the ship. I examine the interior spaces of the trucks as I swim past each one. The steering wheels, gauges, pedals and stick shift are all intact, but the springs are all that remains of the seat cushions. 


            As I pass over the hood of the last dump truck, I can now see the probable reason why all the glass windows on these trucks are blown out. There is hole in the hull caused by an external explosion on the port side that is just big enough to swim through. Evidence of the detonation is all around me. Most of the body of a truck that was parked adjacent to the hole is gone; the solid steel chassis is severely bent and the rubber tires are scorched and melted.

            At this point, I glance at my dive computer and realize my stay at this depth is over. I pass another piece of machinery as I slowly ascend out of the cargo hold. A steamroller hangs perilously off the second floor and propped up only by one of the remaining rusted crossbeams. My head emerges from the dark, confined and silted quarters below to the open sunlit spaces on deck. I turn my light off and begin to breathe a little easier. Although I have just seen the highlights of the Hoki Maru, this dive is far from over.


            I begin swimming forward toward the bow and discover lush soft corals, sea fans and large magnificent sea anemone’s four feet across littering the deck. A school of long nose emperor fish hunts aggressively thrusting their snouts in to the cracks and crevices of the corals in the hope of finding prey. Several big eye trevally and a few napoleon wrasse tags along in the hope of joining in on the spoils of the hunt.  I even spot gray reef sharks circling overhead. This wreck, transformed to coral reef, has a plentitude of marine life. The warm blue water makes the scenery all the more surreal.



Trucks in the hold of the Hoki Maru. 

                        As I swim forward, the wreck becomes shallower until I come across a large section of the deck that is peeled back upon itself like an opened sardine can. Once I get to the edge of the wreck, I look out and all I can see are hull plates and twisted metal lying in the sand all around me. Any semblance of a ship is gone. The thick plating are bent as though they were made of putty. I gaze out at the destruction and contemplate the magnitude of the blast before me. I wonder in awe at the sight, but dread the fate of those that were anywhere near when the bombs ripped through the deck, igniting the deadly chain reaction of explosions below.


            When I come to my senses, I see a small opening in the debris and cannot resist the urge to explore within. I enter the hole and switch on my dive light. Lying before me, there are hundreds if not thousands of beer bottles with the name of Dainippon Brewery Co. imprinted in the glass. I am in what appears to be cargo hold number 3. The ceiling to the hold is completely blocked off by the decking that was peeled back from the explosion. The further I travel down the more bottles I see. Many of them are sitting perfectly aligned and nestled next to each other in the deep silt. The wooden cases the beer was shipped in have long since rotted away, along with the tin caps, leaving the empty bottles behind.


            I’m stupefied as to why the Japanese would allocate such valuable cargo space during wartime to non-essential supplies such as alcohol. Could it be that alcohol was used as a means of improving moral and hence placating the soldiers? Is it easier to pursued men to commit atrocities while under the influence of drugs?


            With once last glance down at my pressure gauge, there is no doubting that it is time to ascend. As I make my way slowly upward, I study the scene below me. As always after such a dive, I ponder the sheer waste of human lives and materials in the form of the rusted remains beneath me. Only the beautiful and prolific marine sanctuary that this once noble ship has become uplifts my forlorn mood. Today, the wrecks of Truk Lagoon serve a purpose beyond that of war.