US company Juliet Marine Systems has invented a boat that uses supercavitation to glide quickly through the water, undetected by radar.
Supercavitation occurs when a fast-moving object creates a low-pressure zone around its surface - a gaseous layer, if the speed is high enough.
In the case of the Ghost craft, this means 900 times less hull friction than water - making for lower fuel costs as well as high speed.
It would have similar applications to attack helicopters, says JMS, delivering forces to beach locations or fighting pirates.
"Any Navy possessing Ghost technology could operate in international waters undetected and would have an overwhelming advantage against conventional ships," says the company.
"Ghost is ideal for piracy patrols and could be sea-based to provide protection from pirate attacks that cost our government an estimated $1.5 billion each year."
The company says its design is scalable, and that it's planning a 150-foot Corvette-sized vessel through a partnership with an unnamed international defense company.
A squadron of Ghosts would be completely undetectable to enemy ship radar and sensors, with each boat carrying thousands of pounds of weapons, including Mark 48 torpedoes. It would be 'virtually unstoppable', says JMS.