Submarine endures a wreck (8)
I believe the answer is:
undersea
'submarine' is the definition.
('undersea' can be a synonym of 'submarine')
'endures a wreck' is the wordplay.
'wreck' is an anagram indicator.
'endures'+'a'='enduresa'
'enduresa' with letters rearranged gives 'UNDERSEA'.
(Other definitions for undersea that I've seen before include "submerged" , "in salt water" , "Below marine surface" , "Submarine" , "Beneath the surface of the ocean" .)