Three anglers were towed to safety yesterday afternoon after losing power on both their engines.
It is thought the 18ft angling boat, with three men onboard, suffered engine failure, possibly due to fuel becoming contaminated with sea water.
The volunteer crew of St Agnes RNLI Lifeboat received a launch request from Falmouth Coastguard and reached the boat, four miles off Trevaunance Cove, at 4:30pm.
The tide and wind were causing the boat to drift and the crew had to act quickly to tow it back to the safety of shore.
John Julian, from the RNLI, said: "The rescued anglers were not in life threatening danger, but were four miles off St Agnes beach with a fresh offshore breeze and choppy seas.
"For a D Class boat this was quite a long and slow tow against a fresh head wind and choppy seas, until the shelter of St Agnes Head was gained for the last mile.
"Towing is an uncommon type of service for our station and the crew were excellent."