USS Callao (IX-205)

USS Callao (IX-205), an unclassified miscellaneous vessel, was the third ship of the United States Navy to be named for Callao, a seaport in Peru. She was built in 1943 and 1944 by P. Smit, Jr. Shipyard, in Rotterdam, the Netherlands, as Externsteine for the Kriegsmarine. The ship was originally named for the unusual Externsteine rock formation investigated by Heinrich Himmler for evidence of cultural significance to early Teutonic folklore and history. Externsteine was employed as a weather observation ship off Shannon Island on the northeast coast of Greenland to aid forecasting of storm events tactically significant to North Atlantic and European combat operations, but was captured on the night of 15 October–16 October 1944 by USCGC Eastwind.

Patrolling aircraft spotted Externsteine camouflaged in a field of unconsolidated pack ice. The Coast Guard icebreaker opened a lead through the ice under cover of darkness. At a range of 4000 yards, the icebreaker fired three salvos from its 5"/38 guns (one short, one over and one across the bow) before closing to hailing range and demanding surrender. At the time, it was the northernmost combat operation ever undertaken by United States forces.

The United States Coast Guard prize crew brought her into Boston, Massachusetts, by way of Reykjavík and NS Argentia, Newfoundland. There she was commissioned into the United States Navy on 24 January 1945 with Lieutenant D. O. Newton, USNR, in command.

Between 30 January 1945 and 4 February she was outfitted at Philadelphia Navy Yard for special experimental work for the Bureau of Ships, and for the next five years carried out tests in the area of Cape May, New Jersey, and Cape Henlopen, Delaware. She was decommissioned on 10 May 1950, and sold 30 September 1950.