Sketch them at harbour with fish (7)
I believe the answer is:
portray
'sketch' is the definition.
(I've seen this before)
'harbour with fish' is the wordplay.
'harbour' becomes 'port' (I've seen this before).
'with' means one lot of letters go next to another.
'fish' becomes 'ray' (ray is a kind of fish).
'port'+'ray'='PORTRAY'
'them at' is the link.
I am not very happy about this link. Some or all of it may be part of another bit of the clue.
Can you help me to learn more?
(Other definitions for portray that I've seen before include "Play" , "Paint a picture" , "Act" , "Delineate" , "Describe in words or make a picture" .)