Armed fishing trawlers against U-boats

Did armed fishing trawlers sink U-boats or fight them successfully in the world wars?

Yes, they fought surface gun actions and could be dangerous opponents, though individual sinking claims require careful source checking.

German commanders sometimes surfaced to use their deck guns against trawlers, especially near home waters. That choice was not always as one-sided as it looked: trawlers could be steadier firing platforms and their crews could be unexpectedly effective. Claims of extraordinary anti-submarine successes still need careful reading against individual war diaries. A later answer clarifies that commissioned trawlers often escorted fishing fleets and might still cast nets while on duty. If a U-boat or E-boat appeared, the crew could cut away costly fishing gear rather than lose time recovering it before fighting.