Vessel churning up water left and right (7)
I believe the answer is:
trawler
'vessel' is the definition.
(trawler is a kind of vessel)
'up water left and right' is the wordplay.
'up' indicates anagramming the letters (letters get chucked up).
'left' becomes 'l' (common abbreviation).
'and' says to put letters next to each other.
'right' becomes 'r' (common abbreviation).
'water'+'l'='waterl'
'waterl' is an anagram of 'trawle'.
'trawle'+'r'='TRAWLER'
'churning' acts as a link.
This may not be correct. It may belong to another bit of the clue.
Can you help me to learn more?
(Other definitions for trawler that I've seen before include "Boat using a net to catch fish" , "Boat that fishes with nets" , "seagoing vessel" , "Type of fishing boat" , "Fishing vessel that drags nets behind it" .)