I suspect that would be more accurately said something like, "The movement used with a bo to block a low kick may have been derived from the motion used to steer a boat with a pole." Even then, I question how often the movements were actually derived from those sources, versus that being used as an example to teach people who knew a similar movement.Staffs have been used as weapons since time immemorial, I doubt they needed to be invented from a stick to steer a boat. Sounds akin to the flying sidekick being used to kick a man off a horse.