Work of little merit in vessel, British tanker (9)
I believe the answer is:
potboiler
'work of little merit' is the definition.
(I've seen this before)
'vessel british tanker' is the wordplay.
'vessel' becomes 'pot' (type of container).
'british' becomes 'b' (abbreviation e.g. in 'BBC').
'tanker' becomes 'oiler' (synonyms).
'pot'+'b'+'oiler'='POTBOILER'
'in' acts as a link.
(Other definitions for potboiler that I've seen before include "work to deliver bread fast" , "Book written just for the money" , "Poor novel" , "Book of little merit designed to make a quick profit" , "hasty work" .)