Fellow sailor transported him as pet (8)
I believe the answer is:
shipmate
'fellow sailor' is the definition.
(another sailor on one's ship)
'transported him as pet' is the wordplay.
'transported' indicates anagramming the letters.
'him'+'as'+'pet'='himaspet'
'himaspet' with letters rearranged gives 'SHIPMATE'.
(Other definitions for shipmate that I've seen before include "Friend on board" , "Sailor on board, a real pal" , "Colleague on board" , "Fellow sailor" , "Fellow crewman" .)