<P> A ship's wheel or boat's wheel is a device used aboard a water vessel to change that vessel's course . Together with the rest of the steering mechanism, it forms part of the helm . It is connected to a mechanical, electric servo, or hydraulic system which alters the vertical angle of the vessel's rudder relative to its hull . In some modern ships the wheel is replaced with a simple toggle that remotely controls an electro - mechanical or electro - hydraulic drive for the rudder, with a rudder position indicator presenting feedback to the helmsman . </P> <P> Prior to the invention of the ship's wheel the helmsman relied on a tiller--a horizontal bar fitted directly to the top of the rudder post--or a whipstaff--a vertical stick acting on the arm of the ship's tiller . </P>

What is the name of the wheel on a pirate ship