One who docks the sailing-ship (7)
I believe the answer is:
clipper
'sailing-ship' is the definition.
(I've seen this before)
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for clipper that I've seen before include "Cutter" , "that has slight collision with another?" , "Trimming instrument" , "Ticket inspector" , "Fast commercial sailing ship" .)