This image was acquired from
flickr. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Keywords from Image Description:
G gun is fired from USCG Cutter Spencer at an unidentified submarine while escorting large Atlantic convoy. Photograph received . Official U.S. Navy Photograph now in the collections of the National Archives. gun is fired from USCG Cutter Spencer at an unidentified submarine while escorting large Atlantic convoy. Photograph