Early in November 1944, we finished all the exteriors, packed up and moved south back to Denham. We had brought back with us the actual open motorboat we used in the film. The actors were able to work in a real boat, surrounded by wind and water machines, and working close up against a back projection screen, so close that they could almost feel the whirling waters of Corryvreckan. One day, when wind and water were at full blast, the boat was pitching and tossing, Roger was roaring at Wendy, Wendy was screaming at Roger, and receiving buckets of water in the face from zealous prop-men, I looked up and saw a mildly surprised face, only a few feet away from mine, watching our eccentric activities with great interest. It was David Niven.
When the whole thing came to a gradual stop, and we dried off, he ventured a remark:
‘Is this a private fight, or can anybody get in on it?’
It was at that very instant that I cast him as Peter, the hero of ‘A Matter of Life and Death’.
— Michael Powell, A Life in Movies (via joan-webster)
