Look very displeased as boat left (5)
I believe the answer is:
scowl
'look' is the definition.
(I know that scowl is a type of look)
'boat left' is the wordplay.
'boat' becomes 'scow' (scow is a kind of boat).
'left' becomes 'l' (common abbreviation).
'scow'+'l'='SCOWL'
'very displeased as' acts as a link.
I am not very happy about this link. Some or all of it may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for scowl that I've seen before include "Bad-tempered expression" , "Lower" , "Grimace" , "Glower; frown" , "Angry frown" .)