'Stemmbogen' was a German naval undertaking to lay a minefield in the area to the west of the Hoek van Holland in the German-occupied Netherlands (12/13 May 1943).

The forces responsible for the operation were Kapitänleutnant Claus Henning von Grumbkow’s 1^st Minensuch-Flottille and Korvettenkapitän Alfred Neumann’s 7^th Minensuch-Flottille supported by Kapitänleutnant Johannes Hartrumpf’s 9^th Räumboots-Flottille. As the German vessels were returning to port, they were intercepted by the British MTB-234, MTB-244, MTB-241 and MTB-232, and in the engagement which followed the German M 8 was sunk by two torpedo hits.