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Who Sank the

Kaibōkan CD-219?

An article in the Fall 2011 edition of The Submarine Review answers the question posed in the title above. The article, "New World War Sinking Discovered," by Commander John D. Alden (USN–ret.), is based on new information provided by Eric Muhlthaler, a widely respected German researcher, who translated some key Japanese documents relevant to this sinking. The 745-ton CD-219 was a larger than usual ASW vessel and resembled a Japanese pre-war minesweeper. According to the Tabular Record of Movement for CD-219 currently posted at, the kaibōkan was torpedoed and sunk on July 15, 1945 at Hakodate harbor, Hokkaido, by American carrier aircraft. Alden argues that on July 12, 1945, the CD-219 was part of a hunter-killer group together with the coastal defense vessel CD-65 and the minesweeper W-24. On the night of July 12-13, 1945, The ASW group was proceeding southward off northeastern Honshu near the important foundry town, Kamaishi. At around 0100 hours on the 13th, the American submarine USS Carp (SS-338) fired two Mark 18-2 torpedoes, one Mark 18-1 torpedo, and a Mark 28 passive homing torpedo (code-named DOGY) at the CD-219, which Carp's captain misidentified as a minesweeper. The three Mark 18 torpedoes missed it, but the passive homing torpedo was attracted to the noise made by the CD-219’s propulsion system. It hit the CD-219 and exploded; the kaibōkan sank quickly near the geographic position 39° 20' N, 142° 18' E. The other two ASW vessels heard explosions seaward and proceeded there to investigate; all they found was some minor floating debris. The CD-219 and its crew were never seen or heard from again. 1

The Submarine Operations Research Group (SORG) report "U. S. Submarine Attacks Listed by Date and Hour of Attack" lists the torpedo attacks discussed above. This report is viewable at the HNSA website in the Patrol Reports section. The Carp’s report for this patrol (her first and only one of the war) includes an endorsement which credits her for sinking 9,800 tons in nine vessels and damaging 2,200 tons in six vessels. However, the postwar JANAC assessment did not score the Carp for sinking any ships. The assessors probably felt the ships credited to the Carp by Comsubpac did not meet the greater than 499 tons threshold. The analysis conducted by Commander Alden and Craig R. McDonald in their latest book credits the Carp for sinking the 169-ton cargo vessel Tenyu Maru, and for probably sinking the 1,535-ton cargo vessel Koga Maru and the 135-ton submarine chaser Cha-59. The new revelation about the CD-219 will add an additional 745 tons to the Carp’s score. The Carp also probably damaged five small coastal freighters and one other small craft in deck gun actions during her only patrol. 2

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1. Alden, John D, "New World War Sinking Discovered," The Submarine Review, Fall 2011, p. 129-132; Hackett, Bob, and Peter Cundall, "IJN Escort CD-219: Tabular Record of Movement," published online at; Submarine war patrol reports on CD, data collected by the Submarine Operations Research Group (SORG) in the report "U. S. Submarine Attacks Listed by Date and Hour of Attack." The term "kaibōkan" refers to a sea defense or coastal defense warship used by the Imperial Japanese Navy during World War II for escort duty and coastal defense. The U. S. Navy classified kaibōkans as escort ships.

2. Submarine war patrol reports on CD, Patrol Report for USS Carp (SS-338); Alden, John D., and Craig R. McDonald, United States and Allied Submarine Successes in the Pacific and Far East During World War II, Fourth Edition, see USS Carp (SS-338), Attack Nos. 4263, 4358, 4359, 4360, 4361, 4362, 4363, 4421, 4423, 4490, 4491, 4492, 4493, 4512, and 4513.