The Duke of Cambridge, 30, was on duty as part of a search and rescue helicopter crew when the alarm was raised that a man had been swept into freezing waves in Blackpool.
A Sea King helicopter, with the Prince onboard, was scrambled from RAF Valley on Anglesey, north Wales, just a few hours in to the New Year, the Daily Mirror reported.
Working with RNLI lifeboat crews, a police helicopter, and coastguard rescue units they spent three and a half hours searching for the missing man.
He had been reported to have been walking his dog in Blackpool with a friend when both men ended up in the water shortly after midnight. The second man was able to get to safety and raise the alarm.
Prince William's Sea King was scrambled around 2am but was stood down 90 minutes later.
His his pregnant wife Kate was spending the New Year with her parents at their home in Buckelbury, Berkshire, unaware of her husband's part into the Hogmanay drama.
