Ernest King US Submarine Dolphin design 1924
One of the earliest designs of the submarine warfare insignia, circa 1924. Enlisted personnel wore this insignia, embroidered in silk, with white silk for blue clothing and blue silk for white clothing, on their right sleeve, midway between the wrist and elbow, a practice that continued until 1950 when the enlisted device became the current silver-plated metal version of the pin. (Photo courtesy of U.S. Naval Undersea Museum)