The Phibian performs for an audience including US military engineers on the Potomac River in Washington DC. Photo / Mark Finkenstaedt

Kiwi rich-lister Alan Gibbs' amphibious vehicle company has turned its focus towards the defence and search and rescue markets, with new craft set to go on sale this year.

In its first public demonstration yesterday, Gibbs latest vehicle, named the Phibian, was displayed on the Potomac River in Washington DC before an audience that included United States military engineers.

Gibbs said the 10m, 500-horsepower Phibian, as well as the 350-horsepower Humdinga craft, was primarily targeted at the global search and rescue market.

The vehicles are capable of travelling at up to130km/h on land and more than 60km/h on water.

"We expect the military to be interested too ... there's a lot of [US] admirals down at the launch [in Washington DC] and they're showing a lot of enthusiasm about it," said the 72-year-old, who has invested $200 million of his capital in the business.

"They are capable of being general-purpose trucks - anything you can do with a truck you can do with these."

The Phibian is mostly constructed out of light carbon fibre and has wheels that retract when it enters the water.

"A vehicle that can perform as well as a multi-terrain vehicle on land while reaching planing speeds on the water means that response will be significantly faster and more seamless," said Gibbs

Also set to hit the market this year is Gibbs Amphibians' Quadski, a quad bike that converts into a jetski and is targeted at the consumer market.

The company has been developing amphibious vehicles for more than 15 years, but has yet to deliver a product to a customer.

The Gibbs Aquada - an amphibious car - had a high-profile launch at London's Royal Victoria Docks in 2003, and was used by Sir Richard Branson in a record-breaking crossing of the English Channel in 2004.

Gibbs said the firm had diverted attention away from the Aquada while it worked on improvements, and was focusing on marketing the trucks and Quadski. The vehicles would be made in the US and Britain, he said.

His company employs six staff in Auckland who worked on developing the Quadski.

Gibbs, who was valued at $420 million in last year's National Business Review Rich List, lives in Britain but also owns a property near the Kaipara Harbour, north of Auckland.