Two men in an inflatable boat, one dressed as a penguin and the other in a Santa costume were towed back into Newlyn harbour on Saturday after they were spotted drifting out to sea off Marazion.
The men claimed they were raising money for the Help the Heroes charity.
Penzance coastguards and the Penlee inshore lifeboat were alerted to the two men, neither of whom were wearing life-jackets.
A spokesperson for Falmouth coastguard said: “ The inshore lifeboat got alongside and found one was dressed as a penguin and the other as Father Christmas. They said they were raising money for the charity, but the Penlee crew persuaded them not to go any further and towed them back to Newlyn.’’