Our side of the river is quite obviously used by the Japanese. They'd spot it at once.
5 seconds sound clip from the The Bridge on the River Kwai movie soundboard.
You can hear this line at 02:04:53.452 in the Blu-ray version of the movie.
Quote context
[...]
- If he knew we were here, it might boost his morale a little.
- If it wasn't for the train, we could set a time fuse and be miles away.
- The problem is where to hide it.
- Our side of the river is quite obviously used by the Japanese. They'd spot it at once.
- Look. Do you see those fallen tree trunks? And the grey rock just below them on that little beach?
- As soon as the bridge goes up whoever's there will have to swim back.
- It's not likely to be a pleasant swim.
- Sir, I was the best swimmer in my course.
[...]