In 1916, the German Realm issued two series of stamps featuring stylized lighthouses for use in sending letters from Germany to the United States via submarine. See the article in the March/April 2019 issue of The Philatelic Beacon for more information about these stamps and their use.
Stylized L/H | 1916 | submarine mail | image courtesy of www.GermanStamps.net
Stylized L/H | 1916 | image courtesy of www.GermanStamps.net
Click here to see all of these “submarine” stamps
