Band on river vessel (5)
I believe the answer is:
liner
'vessel' is the definition.
(liner is a kind of vessel)
'band on river' is the wordplay.
'band' becomes 'line' ().
'on river' becomes 'r' (I've seen this in other clues).
'line'+'r'='LINER'
(Other definitions for liner that I've seen before include "Craft" , "that's put in bin" , "Large passenger-ship" , "cover for interior" , "cruise vessel" .)