In early 1945, the German 31st Infantry Division was trapped on the Hel Peninsula, a heavily fortified 35-km long sand bar peninsula off of Gdańsk (Danzig), Poland. Resupply of the Division was accomplished via the sea.
Beginning in March 1945, the Hela U-Boat Issue was printed by the Division’s mapping unit. It was intended for use on mail transported by U-boats supplying the Division, but due to the fact that surface naval traffic never ceased, the stamps were never used as intended. They can be found used on mail which traveled via surface traffic.