Canoe built for Pacific, eg (5)
I believe the answer is:
'pacific eg' is the definition.
(pacific is a kind of ocean)
'canoe built' is the wordplay.
'built' is an anagram indicator.
'canoe' with letters rearranged gives 'OCEAN'.
'for' acts as a link.
(Other definitions for ocean that I've seen before include "A mighty sea" , "Major sea" , "The deep" , "Quantity of water" , "Large stretch of water" .)