Previous thread from years ago.
IIRC the Margaret Cornish story was that during the war, some IW lady crews were in the Boat Inn, Stoke Bruerne, having had a bad trip through the tunnel. They were complaining to each other about the bend and being balked by a slow, heavily laden boat with dim lights.
After a minute or two they realised that the pub had fallen silent, everyone listening to their tale.
It seems that long ago a boat had sunk in the tunnel with the loss of all hands, and of course there's no bend.............