The Aquada, which transforms from sleek sports car to jet-propelled boat at the touch of a button, looks like something straight out of a James Bond movie. Powered by a 175hp V6 petrol engine, the Aquada can reach speeds of up to 160kmh on land and 50kmh on water. It has a price tag of around $400,000.

Mr Gibbs, who studied engineering at Canterbury, believes the technology behind the Aquada is the most significant development in the automotive world since the Model T Ford.

It is the result of seven years' work by a team of 70 engineers and designers. Working with the team in England for the past year has been Canterbury engineering graduate, Alastair Rose.

The problem with previous amphibious designs was the drag created by the wheels as they moved through the water. With the Aquada the wheels are raised while remaining connected to the drive shafts.

Dr Alexander, a former design manager at the Hamilton jet plant in Christchurch, said the Aquada worked on the same principle as a jet boat.

"It has a shaft connection to the engine so the engine drives an impeller - a type of propellor that sits inside the jet. It is like a jet boat arrangement but it also drives the wheels," Dr Alexander explained.

"Previous amphibious vehicles tended to go at displacement speeds, that is up to about 12kph on the water. This one gets up on a plane and can go 50kmh - it can even tow a water skier. It is not the first amphibious vehicle to plane but it is certainly the first commercial one."

Dr Alexander has watched with interest the media frenzy surrounding the launch of the Aquada on the River Thames last week. Until now, the secrecy surrounding the project has prevented him from speaking out about his involvement.

He was first contacted by Mr Gibbs for advice in 1997 and has since been involved in on-going consultancy work through Canterprise, reviewing the jet design and in particular developing the impeller. He went to England in 2001 to brief the staff about water jets.

Dr Alexander also spent last December and January in England working with the team testing on a private lake south of Coventry, fine-tuning the vehicle in preparation for its launch.

"It was hard work. We were testing it in the middle of a British winter. The flashy James Bond image pales pretty quickly when you are out there in the freezing cold."

But Dr Alexander said it was exciting taking the vehicle for a test drive.

"It is uncanny because all the cues inside the vehicle say you are driving a car, but outside it's a boat. You are sitting there at the steering wheel, with your foot on the pedal but instead of the roadside going past, it's water."

Dr Alexander sees the Aquada as a forerunner to a future range of workhouse vehicles.

"This is the flash sports car version. I'd rather have a pick-up truck version. There are huge possibilities for amphibious vehicles in other fields including emergency services and the military."

During his PhD studies at Canterbury University in the early 1980s, Dr Alexander worked on amphibious designs and made his own radio-controlled model. He is now developing a full-scale prototype but stressed the design was quite different from that used in the Aquada.

Dr Alexander said his department had been working on water-jet research for some time so it was not surprising that Mr Gibbs contacted the University for advice.

"If you want to make a car you go to the English Midlands but no area in England specialises in jets. Canterbury does. This is where Hamilton jets started, this is where the jet boat developed. It is quite appropriate that the expertise should be found in Canterbury and in this University."