Yank in powerful boat (3)
I believe the answer is:
tug
I believe this clue is a double definition.
'yank' is the first definition.
(both can mean to pull sharply)
'powerful boat' is the second definition.
(I've seen this before)
'in' is the link.
(Other definitions for tug that I've seen before include "Tow (of war?)" , "Boat to pull larger one" , "Haul" , "Small boat for towing others" , "Pull jerkily" .)