Vessel docked next to port delivers wine (5)
I believe the answer is:
rioja
'wine' is the definition.
(Rioja is an example)
'vessel docked next to port' is the wordplay.
'vessel' becomes 'jar' (type of container).
'docked' means to remove the last letter (to dock can mean to remove the tail of an animal).
'next to' means one lot of letters go next to another.
'port' becomes 'rio' (Rio de Janeiro is a port).
'jar' with its final letter taken off is 'ja'.
'ja' put after 'rio' is 'RIOJA'.
'delivers' is the link.
(Other definitions for rioja that I've seen before include "Popular Spanish wine" , "Spanish wine type" , "Spanish table wine" , "Dry red wine from Spain" , "Wine from northern Spain" .)