The Nagano Maru was a 345ft/105m, 3,824-ton passenger-cargo ship built for the prestigious Nippon Yusen Kaisha of Tokyo, Japan (“N.Y.K. Line”) in 1917. The word ‘Maru’ designates a merchant vessel. Following her requisition by the Japanese Navy for wartime duties, she performed many cargo and transport runs for both the Japanese Navy and the Japanese Army. The name of the ship was seen in numerous coded radio messages indicating that she made many runs between the Empire and Singapore. Intelligence files also indicated that she suffered unspecified bomb damage on April 15th 1942 while in Cebu, Philippines.
The Nagano Maru was the target of Allied planes on both days of Operation Hailstorm. On February 17th 1944 while she was at anchor at the 4th Fleet Anchorage east of Dublon Island, planes from the USS Essex reportedly were successful in hitting her with two to four 500-lb. bombs causing secondary explosions and fires. The following day she was attacked again by planes from the USS Essex and suffered two more bomb hits, one amidships and one on the stern. When the planes departed, fires were raging aboard the ship. On February 24th 1944 intercepted radio messages indicated that she had sunk, and that there were 59 surviving officers and crew.
She rests on an even keel with a 20-degree list to port. The superstructure is at 140ft/42m feet, the deck at 165ft/50m and the sea bottom at 210ft/64m. She lies almost in the geographic center of the cluster of wrecks in the 4th Fleet Anchorage east of Dublon Island. Only technical divers visit the Nagano Maru due to its deep depths.
Within the bridge superstructure almost all of the wooden decks have been consumed by fire allowing the diver to penetrate down from the top through the skeletal steel framework beams. Various cargo items can be found throughout the ship together with a collection of china and serving items. A large intact flatbed truck, a second truck, bulldozer or prime mover truck, machinery items, detached trailers, and a diesel roller can all be found in various holds.