Bargees in rough water (6,3)
I believe the answer is:
bering sea
'water' is the definition.
(Bering Sea is an example)
'bargees in rough' is the wordplay.
'rough' indicates an anagram (a rough or broken ordering of the letters).
'bargees'+'in'='bargeesin'
'bargeesin' with letters rearranged gives 'BERING SEA'.
(Other definitions for bering sea that I've seen before include "body of water" , "lot of cold water" , "Water between Russia and Alaska" , "stretch of water" , "deep water?" .)