Is it a car? Is it a boat? Branson puts his foot down for a cross-Channel record

It does a creditable 100mph on land but an even more impressive 30mph on water. It took 70 engineers and designers seven years to build. Its transformation from sports car to speedboat takes seconds: the driver presses a button and the wheels pull into the side of the car.

And yesterday Sir Richard Branson demonstrated the extraordinary qualities of the Gibbs Aquada by taking it for a spin (or perhaps that should be a roll?) on the English Channel.

The Virgin entrepreneur "drove" from Dover to Calais in one hour and 40 minutes, setting a new cross-Channel record for an amphibious vehicle. Fittingly, on the day after English football was humiliated by the French, he took the record from two Frenchmen with a time more than four hours quicker.

Never short of an eye-catching picture opportunity, Sir Richard completed the journey in a dinner jacket and bow tie. When he rolled on to wooden ramps placed on the beach at Calais, he crossed a finish line on the promenade to be greeted by the town's mayor. An adjudicator from Guinness World Records gave the official time - measured from the moment he hit the water in Dover to the vehicle touching land in France - as one hour, 40 minutes and six seconds.

Ever since Roger Moore used an "underwater Lotus" in the 1977 Bond film The Spy Who Loved Me, amphibious cars have held a fascination for wealthy adventurers.

Yesterday, conditions in the Channel were far from challenging, with slight seas and light winds, although Sir Richard was forced occasionally to use the windscreen wipers to remove sea spray that impaired his view. "A couple of waves caused by some ferries went straight over the top of us but otherwise it went really well," he said. "It is a great beast. It drives fantastically well on land and then it turns into the most remarkable boat on water."

Sir Richard, whose record-setting escapades have most famously centred on hot-air ballooning, set a transatlantic speedboat record in 1986. He said he thought he had taken the Aquada to speeds approaching its maximum of 30mph. But for much of the crossing the vehicle glided across the calm surface of the Channel at 20mph as a flotilla of other vessels, including an RNLI lifeboat, accompanied the vessel. A Gibbs engineer sat in the passenger seat of the vehicle, which had been adapted to cope with the sea conditions, with a strong pump installed to remove excess water.

The previous fastest amphibious crossing had been made in the 1960s by two Frenchmen, whose six-hour trip in an "amphicar" wrested the record of seven hours and 33 minutes from Ben Carlin, an Englishman.

Yesterday's stunt was part of celebrations to mark the 20th anniversary of Sir Richard's airline, Virgin Atlantic. One of its jets flew over the white cliffs of Dover as he set off.

The Aquada, described as the ultimate "boy's toy", propels itself by sucking up water and spewing it out of the back of the vehicle. Sir Richard is supplementing his fleet of 250 limousines with three Aquadas to ferry customers from London to Heathrow. "On a busy day when the traffic's bad in London we could take up to an hour off the journey time," he said.

The vehicle, which is built by Gibbs Technologies in Nuneaton, Warwickshire, is on sale to the public. The price? £75,000.