Draw a vessel (3)
I believe the answer is:
tug
I believe this clue is a double definition.
'draw' is the first definition.
(I know that tug is a type of tow)
'a vessel' is the second definition.
(I know that tug is a type of service vessel)
(Other definitions for tug that I've seen before include "Pull vigorously, yank" , "Pull sharply" , "Pull hard or suddenly" , "draw with some effort" , "Pull like small boat" .)