Hard getting into dirty-looking small boat (6)
I believe the answer is:
dinghy
'small boat' is the definition.
(dinghy is a kind of small boat)
'hard getting into dirty-looking' is the wordplay.
'hard' becomes 'h'.
'getting into' is an insertion indicator.
'dirty-looking' becomes 'dingy'.
'h' inserted into 'dingy' is 'DINGHY'.
(Other definitions for dinghy that I've seen before include "craft" , "Small open boat, maybe a rubber inflatable" , "Small boat, may be a rubber inflatable" , "vessel" , "little boat" .)