Get fair wind in vessel (7)
I believe the answer is:
frigate
'vessel' is the definition.
(frigate is a kind of vessel)
'get fair wind' is the wordplay.
'wind' indicates anagramming the letters.
'get'+'fair'='getfair'
'getfair' anagrammed gives 'FRIGATE'.
'in' acts as a link.
(Other definitions for frigate that I've seen before include "Warship; -- bird" , "Ship" , "US warship" , "Type of warship" , "Warship - seabird" .)