Just like to respond to Howard Morley's comments. The dam's raids were urgently needed, and it took only a few months to form 617, train them and attack the dams. Quite a feat I'm sure you'll agree. The film nicely conveys the struggles and the friendships of the crews, put together from the best of the Commonwealth fliers. Even if the screenplay does take some rather large liberties with the story.
As to Guy, he was killed in 1944 on his way back from acting as Master Bomber on a raid over Germany. His Mosquito crashed in Holland, killing him and his navigator. To this day there are no explanations for the crash. Guy should not have been flying at all, but he was so desperate to get back in the air that Bomber Harris gave in and let him. A tragedy. Of the crew of G-George (Guy's ship on the raid) none of them survived the war. The crew crashed whilst trying to bomb the Dortmund-Ems canal later in 1943.
The film is a fitting tribute to the raid, and the massive losses of 617. Of the 19 ships to go out, 11 came back. Of the 77 crew lost on the raid, only 1 survived. This is why the dams were not bombed again. And the problem with the Sorpe was that it was an earth damn, the bombs were not very effective as with the Eder and Moehne.
How do I know all this? My Great-grandmother was a Gibson.
Watch the film and marvel.
