Rudder control (6)
I believe the answer is:
tiller
'rudder control' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for tiller that I've seen before include "Handle for turning rudder" , "Bar that turns rudder in small boat" , "Bar that manipulates rudder" , "Boat steerer" , "What boatman uses" .)