Wartime History
During the Pacific War, Tonelik Island was fortified with defenses to protect the entrance of North Pass (Mochonap). The perimeter of this island was mined with 200 Navy beach mines in two rows at six meter intervals, the first row 50m offshore and the second 70m.

In February 1942 a sound room (listening post) constructed from coral was built for the mine fields placed into North Pass, connected to two lines of six Type 92 mines in North Pass. Inside the sound room was a monitoring station for detector coils in North Pass including an automatic and visual detector writing on paper for each coil. Adjacent was a generator room with a 25kw generator. An underwater cable for telephone, telegraph and radio connected the island to Dublon Island.

The island was defended by sixty-six personnel from the Imperial Japanese Navy (IJN), 41st Naval Guard Force. Installations included two observation towers, a barracks 120' x 35' connected by a corridor to a 30' x 50' annex. The island's primary defenses were two 14cm coastal defense guns (5.9" guns) with shields in revetted emplacements and magazines. Nearby was a 90cm searchlight with sound locator plus comparator. Also, a 1.5m range finder.

American missions against Tonelik
February 17–April 29, 1944

After February 17-18, 1944 "Operation Hailstone" carrier air raids, both guns were removed and relocated to positions inside caves on the inner islands. Tonelik Island was defended by the Japanese until the official surrender of Japan in September 1945.

References
WWII Wrecks of the Truk Lagoon pages 17, 89 (map), 90, 93, 150, 242, 402, 515 (index)

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Last Updated
March 20, 2022