St. Nazaire Raid

The raid on St. Nazaire in March 1942 remains one of the outstanding acts of heroism in World War Two. More VC’s were won during the raid than at any other operation in World War Two that took same amount of time. St. Nazaire, on the west coast of France, had dry docks that the Allies had to put out of action if the Battle of the Atlantic was going to be won.
http://www.historylearningsite.co.uk/world-war-two/war-in-the-atlantic/the-1942-raid-on-st-nazaire/
https://en.wikipedia.org/wiki/St_Nazaire_Raid