Making an entrance in a test run past the downtown skyline in San Francisco Bay last Thursday, 18 January, this is the ‘Proteus’. Designed by engineer and inventor Ugo Conti, it is a prototype of a wave adaptive modular vessel, or WAM-V. Named after a Greek God of the sea, it certainly looks like a modern myth come to life.

The Proteus is 100ft long, and has twin hulls connected to each other and a control cabin by four metal legs. The legs ride on titanium springs that act as shock absorbers, bending to allow the WAM-V to adjust to the surface of the water. The vessel is powered by two 255 horsepower marine diesels and displaces 12 tonnes fully loaded. Fuel is stored in the flexible pontoons. It can carry 2 tons of cargo, and can be operated by a crew of two. The cabin, which sleeps four, can be lowered into the water, ‘like a helicopter landing,’ says Conti, and sail off on its own.

However impressive it may look, the futuristic design doesn’t look likely to be pulling the punters in at Excel anytime soon. However, Conti claims it does have a number of commercial and environmental applications: ‘It can go many thousands of miles to deliver something. It can also enter shallow lagoons in faraway places, help scientists and would be useful in search and rescue operations.

Conti would not say how much the prototype had cost. ‘We are still adding that up,’ said Isabella Conti, the inventor’s wife and a vice president of Marine Advanced Research. The couple would also not disclose the vessel’s speed, pending full sea trials.

Jim Jessie, a yachtsman who has been sailing San Francisco Bay for more than 65 years, has never seen anything like it. “It’s different,” he said as he watched the Proteus slink over the wake of a passing boat, its hulls flexing. “It wiggles like a porpoise or a whale,” he said. That’s the whole point, said Conti. Conventional boats cut through the waves. The WAM-V slides over them. “It is not fighting the waves,” he said.

Conti commented that the idea for the WAM-V technology had come to him gradually, over many years of sailing. ‘I liked flexible boats,’ he said, ‘so I decided to push it to the limit. It is very much experimental. You have to be crazy and old to do this,’ said the 68-year-old: ‘When you are old, you can risk more. You have nothing to lose.’