Background
I don't know why we need fictional action movies -- there are more than enough tales of derring-do in the real world and in my book Operation CHARIOT, the raid on St Nazaire, is right up there near the top.
The British were ever concerned about the various German battleships, battle-cruisers, etc., and numerous air raids were flown to sink or cripple them in port, damage the ports facilities, etc. One such target was to render the graving, or Normandie, dock at St Nazaire incapable of handling Tirpitz and thus forcing her off the western coast of France -- from this was born OPERATION CHARIOT. The basic plan was to disguise a ship to look like a German patrol boat, load it with explosives, and ram it into the Normandie Dock, rendering it useless. The secondary objective was to destroy port facilities and smaller docks such that the port was rendered tidal and thus severely restrict use by U-boats and other vessels.