Hiawatha's transport in stormy ocean (5)
I believe the answer is:
canoe
'hiawatha's transport' is the definition.
(I've seen this in another clue)
'stormy ocean' is the wordplay.
'stormy' indicates an anagram (stormy suggests disruption).
'ocean' is an anagram of 'CANOE'.
'in' acts as a link.
(Other definitions for canoe that I've seen before include "Hunting vessel originating in Haiti" , "Boat that's paddled" , "Kayak, for instance" , "Ocean (anag)" , "Small boat with paddles" .)