From Wikipedia

The Greatest Raid Of All

The St. Nazaire Raid (also called Operation Chariot) was a successful British seaborne attack on the heavily defended docks of St. Nazaire in occupied France on the night of March 28, 1942 during World War II. The operation was undertaken by Royal Navy and Army Commando units under the auspices of Louis Mountbatten's Combined Operations. St. Nazaire was targeted as the loss of its dry dock would force any large German warship in need of repairs, namely the Tirpitz, to return to home waters rather than seek safe haven in the Atlantic coast.

The obsolete destroyer HMS Campbeltown commanded by Stephen Halden Beattie and accompanied by 18 shallow draft boats, rammed the St. Nazaire lock gates and was blown up, ending use of the dock. Commandos landed on the docks and destroyed other dock structures before attempting to fight their way out. All but 27 of the commandos were either killed or captured: 22 escaped back to Britain in the Motor Torpedo Boats and 5 escaped to the Spanish border. Five Victoria Crosses were awarded to men involved in the raid, which has been called The Greatest Raid of All.