National Museum of the U.S. Navy

The Bogue-class escort carrier, USS Block Island (ACV-21), was commissioned on March 8, 1943, at Seattle-Tacoma Shipbuilding Corporation, Tacoma, Washington.  Originally, she was classiifed as (AVG-21) until August 1942.  Block Island pioneered new anti-submarine warfare (ASW) techniques after transiting to participate in the Battle of the Atlantic.  In July 1943, she was reclassified to (CVE-21).  On October 28, Block Island's planes sank U-220.   On March 17, 1944, along with destroyer escorts, her aircraft sank U-801, which was followed with her aircraft sinking U-1059 on March 19, 1944.   Along with USS Buckley (DE-51), she assisted in sinking U-66 on May 6, 1944.  On May 29, 1944, German U-boat, U-549, torpedoed and sank Block Island west-northwest of the Canary Islands.  She was the only U.S. carrier lost in the Atlantic during World War II. 

Image:  19-N-42693:  USS Block Island (ACV-21) on sea trials, March 1943.  Starboard, broadside view.  Official U.S. Navy Photograph, now in the collections of the National Archives.