Inside the I-169

September 07, 2020  •  2 Comments

I-169Intact stern to the left; bow to the right

Composite of the I-169

The Dive TeamEri Urmino on left who goes by Umi which means Ocean in Japanese; Keisuke on right and the author center. The Team

You might think living and working in Truk Lagoon offers me unlimited access to the wrecks and the ability to photograph them the way I want, anytime I want but, that just isn't the case. Guest satisfaction on board the Odyssey always takes precedence over my photography and I always have guests. That was until Truk Lagoon closed to tourism in March leaving me with free time and a long list of shots to work on. I might as well make the best of a bad situation. 

Engine RoomKeisuke (right) and Eri (left inspect the controls and gauges of the twin engines.
Shortly after Truk closed I was fortunate to meet two Japanese dive pros who were also stuck in Truk. Treasures dive operators, Keisuke Yokota (owner) and Eri Umino (dive guide) were eager to join me to dive and photograph the wrecks in a way we have not been able to do because of our obligations to our guests. One such dive on our "to-do" list was the Japanese submarine I-169. Although we had dived the outside of the wreck before, none of us have ever penetrated inside. It was time to make plan.

The I-169

The crew of the historic I-169 met a grizzly fate on April 1944 when the vessel made a routine emergency dive during a US air raid and was to never see daylight again. A vital valve had been left open flooding the control room preventing re-surfacing. After several failed rescue attempts the survivors within perished from suffocation. Salvage work continued for another 6 weeks with only 32 bodies recovered. Not wanting the sub to fall into enemy hands the Japanese command at Truk destroyed half of the vessel forward of the conning tower. In August of 1973 a Japanese salvage team removed the human remains and personal effects of 70 additional personnel and conducted a Shinto funeral in town.

Engine Room HatchKeisuke enters the engine room through the aft water tight hatch. Training 

Due to the confined spaces and a single small hatch as an entrance and exit point, penetrating the I-169 requires advanced training and coordinated teamwork. Eri, Keisuke and later on Norio Kaneko dived with me from the Odyssey tender for several months before we developed a trust in each others abilities. You want to make sure the person next to you inside a metal tube at 130'/40m can handle stress in a situation and not panic. Only after we acclimated to each other did we discuss an attempt at a penetration dive into the I-169; one of the more complex dives we have made. 

ExplorersUmi investigating machinery in the engine room. The Dive

At first glance I knew it would be difficult entering wearing twin tanks and carrying a myriad of photo gear. My two dive buddies wisely let me attempt squeezing through the outer hatch first while they waited safely outside. After a minute of cautious adjusting and wiggling I found myself in the aft torpedo room (which is not particularly spacious). Looking forward I saw another circular hatch that was only half open. Getting through it was even more harrowing than the outer hatches. With some cautious maneuvering I found myself in the circuit breaker room and then the generator room after that. Continuing on and looking forward I saw yet another circular water tight hatch leading into the engine room; the last intact section of the I-169. At this point, perceptual narrowing is taking place and my Communication TubesThis station in the generator room has 6 communication tubes aligned in a row. The red coloration may be a chemical reaction seawater is having with the bronze metal.
heart rate is increasing. There is no quick egress inside a sub. Any problems encountered, such as gear malfunction or entanglement must be dealt with quickly and calmly. I entered the engine room and then paused a moment to acclimate. It is told that the first divers to enter the sub in the early 70's found a pile of bones on top of the engines indicating the crew may have climbed up to reach the last pockets of air as the ship slowly flooded. Thinking of the souls that perished within was not conducive to keeping my cool so I focused the camera and began shooting. Numerous valve handles, gauges, ducts and unknown equipment are at every glance in this complex heart of the ship. The twin diesels were powerful and propelled the I-169 at an impressive top speed of 23 knots while surfaced. Swimming forward between the two behemoths to the control panel yielded a view of a complex array of gauges and plenty of whatchamacallits. With Keisuke coming in behind me, I turned and snapped a few photos while he posed like a pro. 

EgressKeisuke egresses from the I-169 on side-mount through the aft hatches. The top hatch is the outer hull. The lower is through the pressure hull. The photo was shot from the opening of the torpedo loading hatch. The End of the Line

At this point we have come to the end of the line. Continuing on is not possible. The hatch forward of us is partially open leads to a blown up section of the sub. It is now time to turn the dive and head back out through the haze we created from our venting bubbles dislodging rust and silt from above. Despite the three of us gingerly swimming through the wreck, silting is unavoidable. We inch our way along periodically checking on each other. Eventually we see the refreshing glow of sunlight emanating down through the hatch. I now have the confidence that getting out should not be an issue since I already managed to get in. I squeezed through the hatches and popped out the other side as if I was reborn. The feeling of excitement and relief came all at once. 

Umi EgressingUmi fits easily through the narrow hatch using side mount technique. A bit more effort is required with the authors twin back mounted tanks. Umi and Suke exit behind me without incident and conduct our decompression for the next 40 minutes before surfacing. We just completed a complex dive without a single issue and are all elated at the experience. That night we sat around the Odyssey dining table, drinking beer and eating chicken wings discussing our next dive. We were in unanimous agreement. We definitely wanted to go back inside the I-169 to continue our survey and take more photos. 


At the writing of this blog we have conducted 6 penetration dives into the sub yielding one or two images per dive. Prior to each dive I conspired with Eri and Keisuke as to what our goals were and how to complete them. Strategy is important when taking photos under these conditions. Each shot must be taken within a few minutes of entering a room before silting occurs, lights must be strategically placed to offer more details of the environment and we need to choreograph our movements so not to throw off our buoyancy. There is little room for error. 

Engine RoomAn eerie apparition or Keisuke emerging from the haze? Diving the I-169

This dive requires training, years of experience and a calm demeanor to pull off. The Odyssey does not permit penetration dives on the I-169. It will lead to conflict and dangerous copy-cat behaviors with too many divers vying to enter. This dive must be done from a private boat with a dive guide willing to take you in and a dive operator willing to allow you to penetrate. A maximum of two divers at time is recommended; three at tops as long as you are coordinated as a team. Silt outs are a major hazard and peak buoyancy is mandatory! A dive operator may require a period of familiarity with any diver before they will conspire to help you with this dive. That includes me. Please contact myself or the other operators before arriving in Truk and requesting a tour inside the I-169. If I can't help I will try to find someone who can but, I make NO promises!

Join Mike in Truk on the Odyssey for Rec•Tec 2022

Engine RoomA close up of the controls of the starboard engine.

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Glenn F(non-registered)
Great story and pictures Mike. I dove the exterior of the I-169 off of the Odyssey in 2010. I stuck my head in the hatch and was amazed at the tight confines within and would never consider attempting a penetration. I’ll leave that to the pro’s like yourself. Thanks again for the pictures and stories from Chuuk. Hope to see you again soon.
Great sorry Mike! Thank you for sharing your experiences.
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