Fishing boat net (5)
I believe the answer is:
trawl
'fishing boat net' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for trawl that I've seen before include "Large net used for fishing" , "seek suitable candidates" , "Large wide-mouthed fishing net, usually dragged" , "fishing expedition" , "Net for fishing at sea" .)