Officer getting a rough ride on ship (9)
I believe the answer is:
brigadier
'officer' is the definition.
(I know this)
'a rough ride on ship' is the wordplay.
'rough' is an anagram indicator (a rough or broken ordering of the letters).
'on' means one lot of letters go next to another.
'ship' becomes 'brig' (I've seen this before).
'ride' is an anagram of 'dier'.
'a'+'dier'='adier'
'adier' after 'brig' is 'BRIGADIER'.
'getting' acts as a link.
(Other definitions for brigadier that I've seen before include "Military leader" , "Rank above colonel" , "Army rank" , "High-ranking army officer" , "Air bridge over to the military officer" .)