Conducted the Second and Third Surveys of the "Blue Boat of Tsukishima"

The Gunjo Foundation, Inc. (hereinafter referred to as “the Foundation”), in collaboration with KDC Holdings Co., Ltd., conducted the second and third Surveys on March 4 and April 25, 2026 (Reiwa 8), regarding the barge boat moored in Tsukishima, Chuo-ku, Tokyo — locally known as the “Blue Boat of Tsukishima” — which was suspected to be a motor launch from the battleship Hiei (hereinafter referred to as “the Vessel”).

Following the inaugural survey on December 15 of last year, the Foundation received specialized information from naval researcher Mr. Yuji Seno. Based on official blueprints of a 15-meter motor launch provided by him, we narrowed down the key target areas and have been conducting intensive surveys.

During the second survey, we performed measurements of the stern, captured 3D data, and conducted a preliminary underwater inspection using GoPro cameras. Additionally, we interviewed Mr. Motohiro Kaneko, the former owner of the Vessel, to document his testimony regarding its provenance and history. The third survey involved a full-scale diving operation based on the official 15-meter motor launch blueprints to inspect the interior and structural status. During this dive, we confirmed that the original lifting hooks for shipboard mounting remain intact at the fore and aft of the keel. Consequently, we have successfully identified the Vessel as a 15-meter motor launch formerly belonging to the Imperial Japanese Navy.

Furthermore, on April 24, Tomotaka Hara (Honorary Chair) and Ryota Ikeda (Director for Maritime), accompanied by Assembly Member Kano Aoki, visited Mr. Uzumi Yoshida, Vice Mayor of Chuo Ward, to provide an explanation regarding the Vessel. Vice Mayor Yoshida offered significant encouragement, stating, “The fact that this vessel has survived for over 80 years suggests that history itself is telling us it must be preserved.” The Foundation will continue to verify the historical facts surrounding the Vessel and deliberate on future preservation policies.

In the third survey, Rekishikan Lavie, a Foundation-Affiliated VTuber, participated to cover the survey activities. The comprehensive results of the series of surveys will be broadcast as part of the “Gunjo Foundation Bulletin” on Rekishikan Lavie’s channel on Saturday, May 23.

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