Powered boat is scrapped (5)
I believe the answer is:
rowed
I believe this clue is a double definition.
'powered boat' is the first definition.
(rowing a boat powers it)
'is scrapped' is the second definition.
(scrap can mean to argue or row)
(Other definitions for rowed that I've seen before include "Took part in regatta, perhaps" , "Used oars" , "Squabbled" , "Sculled" , "Propelled by oars" .)