helm [helms](tiller (or, in a large ship, the wheel) which is used to control the rudder of a marine vessel; entire steering apparatus of a vessel) noun [UK: helm] [US: ˈhelm]
rudder [rudders](underwater vane used to steer a vessel) noun [UK: ˈrʌ.də(r)] [US: ˈrʌ.dər]