Sailor to obtain his goal (6)
I believe the answer is:
target
'his goal' is the definition.
'target' can be an answer for 'goal' (target is a kind of goal). I'm not sure about the 'his' bit.
'sailor to obtain' is the wordplay.
'sailor' becomes 'tar' (term for a sailor).
'to obtain' becomes 'get' (synonyms).
'tar'+'get'='TARGET'
Can you help me to learn more?
(Other definitions for target that I've seen before include "purpose" , "One aimed at" , "Object to be attained by archers (or fund raisers?)" , "Object to be aimed at" , "desired objective" .)