Officer to get boat and change direction (9)
I believe the answer is:
subaltern
'officer' is the definition.
(subaltern is a kind of officer)
'boat and change direction' is the wordplay.
'boat' becomes 'sub' (I've seen this before).
'and' means one lot of letters go next to another.
'change' becomes 'alter' (synonyms).
'direction' becomes 'n' (N is an example).
'sub'+'alter'+'n'='SUBALTERN'
'to get' acts as a link.
(Other definitions for subaltern that I've seen before include "Lesser official" , "Army officer below the rank of captain" , "Junior officer" .)