The Calshot lifeboat mooring snagged the triple-bladed propeller of a Sunderland flying boat which sank just off Calshot spit 50 years ago, then a hive of military activity due to RAF Calshot’s base there.

Measuring approximately 12 feet across, the discovery came about after the lifeboat’s mooring became snagged on something, leading RNLI Calshot volunteer crew member and lifeboat mechanic, Mike Lawrence, to investigate.

Mike said: ‘A few days ago we realised the mooring chain which anchors our all-weather lifeboat near the jetty was stuck on something. I started up the motors and using the power of the lifeboat I tried to pull the mooring free. However, I felt something ‘pop’ and I knew that we’d dislodged something on the seabed. I also knew it wasn’t the sort of thing one person could lift!’

Further investigation by contractors working for the RNLI, revealed that the ‘pop’ was most likely the sound of the propeller being pulled free from the wing of the Sunderland flying boat. The craft was hugely popular throughout the Second World War and was used as a passenger plane as well as a fighter plane and for munitions drops.

Before its closure in 1961, RAF Calshot was the main seaplane and flying boat development and training unit in the UK, with the landing area sheltered by the mainland – to the west, north and east – and the Isle of Wight, a few miles away to the south on the other side of the Solent.

Bryan Laughlin, Lifeboat Operations Manager at Calshot RNLI lifeboat station, said the find was not the sort of thing you expect in the day to day running of the charity that saves lives at sea. He said: ‘When we pulled it up we were all rather surprised and a little bit overwhelmed to be seeing a piece of aviation history right before our eyes. In line with the law we alerted the Maritime and Coastguard Agency’s Receiver of Wreck, who will ensure the find is dealt with according to the laws relating to finds of this nature. We hope, though, that it will end up in a good home, somewhere like the aviation museum in Southampton.’