The inshore lifeboat from Falmouth was called to the aid of a yacht which was taking on water at a visitors' mooring off Prince of Wales Pier on Saturday afternoon.
The boat was returning to Helford Village Regatta from an incident in the Carrick Roads at around 4.15pm when it was asked to assist the 37ft yacht Demoiselle
Upon arrival they discovered that the water was up to the cabin floor.
An RNLI spokesperson said: "The inshore lifeboat returned to the station and collected a salvage pump which was then used to reduce the water level allowing the source to be identified.
"With the yachts pumps holding the flow the inshore lifeboat towed the yacht up to the Falmouth Marina in the Penryn River where arrangements were made to lift the vessel out of the water."
The entry point of the water was believed to have been from the seal on the propeller shaft.