[Saipan] Wreck (sunken ship) investigation report (Saipan Underwater Cultural Heritage Trail)

Asahi Shimbun Evening Edition (only a portion published due to copyright issues)

　We posted the result report on social media around May, but I accidentally didn't post it on this blog, so many people probably overlooked it. Also, since it was the subject of a lecture at a diving event that followed immediately after, I did not write about it in detail. As the Asahi Shimbun evening edition on October 25th published an article about the current state of Saipan's wrecks, conservation projects, and the efforts of local guides, I would like to write about it here again.

https://www.asahi.com/articles/ASRBS6JQVRBDTOLB001.html

In April of this year, I headed to Saipan. It takes 3.5 hours by direct flight from Narita to Saipan. Currently, the number of direct flights is three per week, which is less than at its peak, but the proximity is still the same as going to Okinawa. The reality is that the number of Japanese tourists on Saipan has decreased considerably recently due to the coronavirus pandemic and above all, the weak yen. When I went there in April, most of the tourists were Korean and there were only a few Japanese.

The purpose of my visit to Saipan was to participate as a team member in a NOAA (National Oceanic and Atmospheric Administration) project, which is led by ECU (East Carolina University).

Saipan Underwater Cultural Heritage Trail Team

Duration is approximately 1 month.

One of the members of this team is Kotaro Yamafune, a Japanese underwater archaeologist, who invited me to be a part of the team.

Saipan is home to many sunken ships and aircraft…

I often use war heritage. In archaeological terms, it is referred to as ``underwater cultural heritage,'' but the fact that both Japan and the United States suffered many casualties in the 1944 Battle of Saipan is evidenced by the many battle sites still on land. I knew there were many points underwater as well, but I was only able to photograph some of them when I visited Saipan previously.

Underwater archeology has always been a field that I have been paying more attention to as I have been working on war heritage with the aim of ``recording'' and ``passing down the generations,'' and this opportunity to be exposed to it is a great opportunity for ``protection'' and ``tradition.'' It was a valuable opportunity to learn about approaches and ways of thinking about things like "preservation."

Scenery of the pier on Saipan Island

Professor Jennifer from ECU, the project leader, is said to be one of the top female researchers of her generation in the world of underwater archaeology, and she welcomed me very warmly. In the second half, the Japanese team from Kyushu University and the Japanese ROV (underwater drone) team also joined and lived under one roof.

I would like to introduce some of the contents of this project.

Saipan Underwater Cultural Heritage Trail - Corrosion Level Measurement

The above photo is an inspection and measurement carried out by drilling a small hole in a sunken ship. Based on the concentration of chemical substances detected there, it is possible to measure the type and progress of corrosion, and by simultaneously recording the oxygen and salt concentrations at that point from the ship, it is possible to consider the best preservation method. The roles of each diver are clear: the two people in the front are in charge of taking measurements, and the two people in the back are in charge of repairing the small hole drilled for measurement with putty once the inspection is complete. did.

Saipan Underwater Cultural Heritage Trail/eDNA Collection

The above photo shows the collection of “eDNA”. eDNA apparently refers to "environmental DNA," and as shown in the photo, by collecting microorganisms attached to ruins (in this case, a sunken ship) and analyzing them, it is possible to improve the environment. It is said that it will be possible to investigate what kinds of living things exist and what kind of influence they have.

Saipan Underwater Cultural Heritage Trail/ROV Unit

The strength of underwater drone (ROV) units is that they can go to depths that divers cannot go to. This time, a team from Kyushu University accompanied the team, and based on maps of the ocean floor topography obtained using multi-beam sonar, they targeted objects with shapes similar to man-made objects and sent underwater drones to investigate them. I thought it was something I could do alone, like with an aerial drone, but I learned a lot from learning that a certain amount of teamwork is required, such as moving ships, the effects of tidal currents, and cable work.

Task Force Dagger diving equipment

The team also includes the Task Force Dagger Special Operations Foundation. The foundation supports sick and injured members of the U.S. Army, Navy, Air Force, and Marine Corps Special Forces (USSOCOM), and is participating in research and exploration as part of their rehabilitation program. The team uses rebreathers and can dive deeper and longer than divers who use open circuits (such as recreational diving). Since some of the members are traumatized, there are rules regarding portrait rights, so I will only introduce the equipment here.

Presentation at American Memorial Park

A public participation presentation of the project was also held. Guests asked questions and a lively discussion ensued. Continuing to protect and maintain cultural heritage requires awareness and understanding not only among those involved but also among citizens.

Saipan Island Type 0 three-seat reconnaissance aircraft

For your reference, I will list here the "wreck" that I dived this time.

・Type 0 three-seat reconnaissance aircraft

・Type 2 flying boat

・3 Sherman tanks (M4 medium tank)

・3 large launch boats

・Shoyasumaru

・LVT (Amtrak) 2 cars

・PB2Y Coronado

・PBM Mariner

・TBF/TBM Avenger

・Steamer (a ship called)

・Sub chaser

Saipan Island, Type 2 flying boat (near the cockpit)

This time, I was very grateful to the guides at the Japanese shops in Saipan. It was a unique sight to see so many Japanese guides going beyond the boundaries of shops at this time to seriously look at the war ruins and work on creating 3D models of them in order to protect them. I would like to take this opportunity to introduce them as they have been introduced on other sites as well.

◉Japanese guides take on battle site preservation activities and underwater photogrammetry (external site)

https://oceana.ne.jp/diving/diving-spot /135137

The photogrammetry introduced above is the specialty of Mr. KOTA and Mr. Yamafune, who approached us this time, and they have many achievements, so if you are interested, please take a look. I want it.

Mr. Yamafune taking a photo of the large launch boat on Saipan Island

I hope to revisit this Saipan Underwater Culture Trail in the near future. At that time, I would like to go with as many friends and interested people as possible, so please keep in mind that ``Tomura is thinking about such things.''

Being involved in this project will be a great asset for me in the future.

Finally, in the December 2023 issue of the monthly "Maru" released on October 25, 2023, Requiem for the Undersea 111 "Saipan's Type 0 three-seat reconnaissance aircraft ”.

I hope you will take a look at this as well.