For those not familiar:
A frog was hopping along the shore of a river looking for a place to cross. He came upon a scorpion sitting on the shore. “Hello, friend frog,” said the scorpion. “It appears you are looking to cross the river. I too want to cross. Would you mind carrying me?”
The frog was taken aback. “Why, if I let you on my back to cross the river, you’d sting me and I would die. I don’t think I’ll do that.”
The scorpion immediately replied, “There is no logic to your concern. If I sting you and you die, I will surely die as well, since I can’t swim. I wouldn’t need a ride if I could swim.”
The frog thought a moment and then said, “Your logic makes sense. Why would you kill me if it would result in your death? Come along and climb on my back and we’ll cross this river.”
The scorpion climbed on the frog’s back and off they went to cross the river.
About halfway across the river, the scorpion raised its tail and stung the frog. The frog was both astounded and disconsolate. “Why did you sting me? Now I will die and you will surely drown and die also.”
The scorpion replied, “I can’t help it. It’s who I am. It’s in my nature.”
I always though it was “common knowledge” that most sailors in the medieval times didn’t know how to swim. It might be an urban legend though.
I’ve heard that it was based on a reasoning that if you end up in the water at sea, you’re going to drown anyway, so it’s better to not be able to swim and just get it over with.
However, knowing that most sailors came from coastal communities, it’s probably pretty unlikely that learning to swim wasn’t a natural part of growing up. Kids have always enjoyed playing in the water.