During the 60's I was a pupil at William Penn North Dulwich. We made an 8mm film. It was called The Magic Coin. When it was rubbed, it made things dissappear. I did the stunt, whilst getting into a row-boat on the lake, the coin was rubbed, the boat dissappeared and I fell in. There was about a foot of water and 9 inches of mud. There were no ridiculous Council regs in those days stopping kids from being kids.