All you that mock! This boat is the result of a very sad tale of woe.
Fred was a speedboat designer, and one day he drew a nice little runabout and put an outboard on the back. He took the drawings along to show his boss. "Ah" said the boss, "but what if the engine should break? It's not unheard of you know and we don't want the bad press of one of our boats being rescued by the gallant men from the RNLI in calm conditions now do we!?"
So Fred went back to his desk and thought about this. And in a Eurika moment thought "I know, I'll put 2 engines on it. That way if one breaks there will be another one to get it home!" But then he thought "but what if two engines fail? Then the boat would still be in trouble..." And in a Eurika moment thought "I know, I'll put 3 engines on it, that way if two break there will still be one to get it home!"
Several hours later the boss came into his office and said "Fred, have you solved that problem with your design?"
"Oh yes" said Fred
"Good, there's been a mix up in the factory and they have to start building something new straight away, send them the drawings now"