Ship’s officer serving time in West, perhaps (4)
I believe the answer is:
mate
'ship's officer' is the definition.
(mate is a kind of ship's officer)
'time in west perhaps' is the wordplay.
'time' becomes 't' (abbreviation).
'in' means one lot of letters goes inside another.
'west perhaps' becomes 'Mae' (actress Mae West).
't' inserted within 'mae' is 'MATE'.
'serving' is the link.
(Other definitions for mate that I've seen before include "tea" , "Spouse or informal friend" , "Fellow member, partner" , "Final move in chess" , "Match" .)