Seafarer, mariner (6)
I believe the answer is:
sailor
I believe this clue is a double definition.
'seafarer' is the first definition.
(I've seen this before)
'mariner' is the second definition.
(I've seen this in another clue)
(Other definitions for sailor that I've seen before include "Tar, AB" , "Old salt" , "Seafarer" , "Sinbad, maybe" , "Person who goes to sea" .)