Two of the last remaining fully operational high-speed World War II motor boats, known as the Spitfires of the Sea, have been saved for Britain thanks to a £580,000 grant.

The boats, which were the fastest of their type, were vital parts of the Allied war effort.

One of the boats, a MGB 81, is an example of the vessel which was active during the US landing at Omaha beach during D-Day.

The other boat, a HSL 102, is the only surviving example of the 100 class high-speed launch which was used at RAF Calshot, near Southampton, Hants, to retrieve shot-down airmen from the sea.

During the war, the HSL vessels saved a total of 10,000 airmen of various nationalities.

The saved HSL 102 also featured in the film Enigma with Kate Winslet in 2001.

Now the National Heritage Memorial Fund has provided the money to enable the Portsmouth Naval Base Property Trust (PNBPT) to purchase the two boats.

Despite an original life expectancy of 20 years, they have both been restored and are on display at Gunwharf Quays Marina, Portsmouth, Hampshire.

It is hoped that one of the boats will be available for charter to enable the public to experience their power.

Peter Goodship, chief executive officer of the PNBPT, said: "These unique craft are a legacy to the heroism of those who crewed them during World War II.

"Both boats made significant contributions to the war effort and saved the lives of many sailors and airmen."

Crewing the boats, which were built at Hythe, near Southampton, was said to be like riding on a massive petrol bomb, as they held 3,000 gallons of fuel and would simply explode if they were shot.

Lieutenant James Shadbolt, a veteran of Royal Navy's 8th Motor Gunboat Flotilla, said: "I'm delighted these two motorboats will now be safeguarded.

"Organisations like NHMF and other generous donors play such a vital role in protecting our precious heritage and those of us who particularly cherish these boats are very grateful."