Deceptive big scree in ocean hazards (8)
I believe the answer is:
icebergs
'ocean hazards' is the definition.
(I've seen this in another clue)
'deceptive big scree' is the wordplay.
'deceptive' indicates anagramming the letters.
'big'+'scree'='bigscree'
'bigscree' anagrammed gives 'ICEBERGS'.
'in' is the link.
(Other definitions for icebergs that I've seen before include "Masses of ice floating at sea" , "Masses of frozen water and lettuces" , "Arctic sea hazards" , "Frozen mountains in the sea" , "Large masses floating at sea in polar regions" .)