Operation Royal Marine

Operation Royal Marine
Part of the Second World War
Soufflenheim and vicinity
Operational scope	Tactical
Location	Rhine, Moselle, Meuse rivers 48°50′N 7°58′E / 48.83°N 7.96°E / 48.83; 7.96
Planned by	Winston Churchill
Commanded by	Commander G. R. S. Wellby
Objective	Obstructing German rivers and canals with fluvial mines
Date	May 1940 (1940-05)
Executed by	Military Intelligence Research [MIR(c)], Royal Navy parties
Outcome	Temporary suspensions of German river traffic and damage to barge barriers and bridges
Sufflenheim Soufflenheim, a commune in the Bas-Rhin department of north-eastern France

Operation Royal Marine was a military operation in May 1940 of the Second World War, during the Battle of France (10 May – 25 June 1940). The British floated fluvial mines down rivers which flowed into Germany from France. The plan was to destroy German bridges, barges and other water transport. After several postponements insisted on by the French government, fearful of German retaliation, the operation began on 10 May 1940, when the German offensive in the west began.

The mines caused some damage and delay to German river traffic on the Rhine from Karlsruhe to Koblenz and damaged bridges and protective barriers. Part of the plan was for Royal Air Force (RAF) bombers to drop the mines into rivers and canals on moonlit nights but this had hardly begun when the campaign ended. The success of the plot was nullified by the Allied defeat and the Franco-German Armistice of 22 June 1940.