Boat; wrench (3)
I believe the answer is:
tug
I believe this clue is a double definition.
'boat' is the first definition.
(tug is a kind of boat)
'wrench' is the second definition.
(I've seen this in another clue)
(Other definitions for tug that I've seen before include "Small ship for pulling" , "Pull like small boat" , "Boat to pull larger ones" , "A sharp pull or a towing boat" , "Small boat for towing others" .)