# Notice also that ships ... are steered by a very small rudder
A rudder is a flat piece of wood or metal at the back of the ship, used to control where it goes. The word "rudder" could also be translated as "tool."
# are driven by strong winds,
"strong winds push them, they"
# are steered by a very small rudder to wherever the pilot desires
"have a small tool that a person can use to control where the ship goes"