L. A. Shafer They Kept the Sea Lanes Open 1918. Great seascape shows a damaged surfaced U-boat surrendering with all hands to an American destroyer. A dazzle-painted (camouflaged) troopship looms on the horizon. The only American World War I poster depicting action at sea. 28×40 near mint, conservation backed.
Bibliography: Walton Rawls Wake Up America! pages 230-231.