Making waves at its unveiling in London on Wednesday, the Aquada, is designed to reach speeds of 160kph (100mph) on land and over 45kph on water, according to Gibbs Technology, which developed the vehicle.
No other road-legal vehicle has so far managed to exceed 10km on water, the company claimed.
Previous attempts have failed because of the vehicles' inability to climb out of the water and skim along the wet stuff.
But the vehicle is likely to be beyond the reach of all but the wealthiest 007-wannabes, with a price tag of $234,000.
It is the brainchild of Alan Gibbs, an entrepreneur from New Zealand who now lives in London. The technology took 70 engineers and designers seven years to develop, with over 60 related inventions patented.
The Aquada, which was put through its paces in the River Thames as journalists watched, is a two-wheel drive which uses unleaded petrol and has an engine of 175 horsepower.
Emerging from London's River
Thames, the vehicle is touted as
an ideal city commuter car
It has no doors, but the driver climbs over the side to get in. The vehicle has a range of 80km and has been designed to go in the sea or fresh water.
Gibbs claims it performs as well as or better than jet boats of a similar size.
"It’s in the first instance a recreational vehicle, a sports car and a sports boat," said Gibbs, who founded Gibbs Technology and is chairman of the group.
"But it could be a city vehicle which avoids commuter congestion. The Thames is a perfect location to make use of this vehicle as it has no speed limit and is greatly under-utilised."