#0006 - Daddy's soft spot

Half? Probably a bold overestimation.

Sailors in general and pirates of that era were not known to be able to swim. The many reasons include that the sea was seen as dangerous, full of monsters and you didn't want to go in; swimming instructors were hard to find and cost money that could be better spent; stopping and turning sailboats was hard and it was unlikely to be able to rescue someone in time anyway and finally: being pragmatic souls, sailors often thought being able to swim would only prolongue the agony after you fell overboard.