The most common and most likely answer to this crossword clue is the 8 letter word TRAWLERS
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Buddy explains!

The straight part
We know that "fishing boats" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case fishing boats = trawlers.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does TRAWLERS mean?
TRAWLERS noun- A fishing boat that uses a trawl net or dragnet to catch fish.
- A fisherman who uses a trawl net.