Depiction of vessel after heading for sea (6)
I believe the answer is:
sketch
'depiction' is the definition.
(thesaurus)
'vessel after heading for sea' is the wordplay.
I cannot quite see how this works, but
'vessel' could be 'ketch' (ketch is a kind of vessel) and 'ketch' is found in the answer.
A single letter 's' remains which might be clued in a way I don't see.
This explanation may well be incorrect...
'of' acts as a link.
Can you help me to learn more?
(Other definitions for sketch that I've seen before include "Short humorous scene" , "Short dramatic scene" , "Portrait" , "Small sailing boat" , "Simple drawing" .)