A once wrecked vessel (5)
I believe the answer is:
canoe
'vessel' is the definition.
(canoe is a kind of vessel)
'a once wrecked' is the wordplay.
'wrecked' indicates anagramming the letters.
'a'+'once'='aonce'
'aonce' anagrammed gives 'CANOE'.
(Other definitions for canoe that I've seen before include "Small boat for paddling" , "Boat (that can be dug out!)" , "Narrow paddle boat" , "Hunting vessel originating in Haiti" , "Light boat propelled by paddle(s)" .)