City slicker driving his flash Merc in the Norfolk lanes, comes upon a ford and an old boy sitting on the fence nearby. Winds his window down and shouts rudely "I say, YOU - is that river shallow enough for me to get across?" To which the old boy replies lazily "Well I should ha' thought so, Sir".
So slicker drives full pelt into the river and the water flows in through his open window. "You idiot", he shouted - "I thought you said it was shallow enough?"
The old boy scratched his brow and replied "Well tha's a rumm'n - the water only come half way up the Master's ducks".....