The winged marine vessel gliding over the surface of Rhode Island’s Narragansett Bay could be the future of coastal transportation or a new kind of warship.

Its maker, REGENT Craft Inc., is betting on both.

The company designed, built and is now testing a prototype of a vessel it calls seaglider – a hybrid between a boat and aircraft that exploits a physics phenomenon called ground effect, the same cushion of air that pelicans and seagulls ride when skimming ocean waves.

The venture is backed by an unusual coalition of influential investors, including Peter Thiel and Mark Cuban, several airlines together with defense and aerospace contractor Lockheed Martin.

Billy Thalheimer co-founded REGENT Craft with Mike Klinker.

The duo honed their skills in aircraft development and design while working in electric aviation at a Boeing subsidiary known as Aurora Flight Sciences.

They both took their first full-scale seaglider prototype for hydrofoil testing in New England’s largest estuary.

"A seaglider is an all-electric flying boat. It is meant for regional coastal transportation to solve the problems of routes that are just too long to drive and you're stuck in traffic, or to fly where it's too expensive and you are stuck in the airport longer than you're in the airplane,” Thalheimer said after testing the vessel.

During the test, the prototype dubbed Viceroy initially rode the waves like a boat and accelerated until it a pair of hydrofoils lifted it out of the water as its 12 electric motors generated a low, electromagnetic whine.

“A seaglider operates in three modes – float, foil and fly. So, you board it at the dock like a boat, then you rise up on hydrofoils that we take from the America's Cup. That gives us high wave tolerance in the harbor and then we fly on a cushion of air over the surface of the water just like a bird flies on, called the ground effect, that gives sea gliders incredible efficiency," Thalheimer said.

A seaglider, with its electric motors distributed across two wings, is simultaneously the fastest boat in the water and the slowest flying machine designed to cruise some 30 feet above the water.

Designers had to come up with creative engineering to get the seaglider to take off in slow speeds that work for hydrofoil travel.

That is because when the vessel exceeds a certain speed – around 50 knots or 50 to 60 miles ( 81 to 97 kilometers) an hour – it boils the water on top of the hydrofoil, even at room temperature, causing the formation of air bubbles and the undesired loss of lift.

“To achieve that very slow flight, this is a configuration called a blown wing. The propellers blow air over the wing and that's why they're distributed. The wing sees fast moving air even though the seaglider moves slowly, and therefore we're tricking the wing into generating very high lift at low speeds,” Thalheimer said. “So that allows us to slow our takeoff and landing speeds to about 50 knots or so – 50 to 60 miles an hour – which is also the top speed of a seagliders on its hydrofoils. And for the first time ever we can overlap those two speed regimes so we can take off from a foil onto our wing."

Engineers also had to come up with high-end digital control systems that would enable mariners to safely operate the vessel, including in hydrofoil mode at high speeds that are necessary for takeoff.

The vessel has at least 12 sensors onboard, three different computer systems together with built-in redundancies and capabilities that control operations, giving its captain the bandwidth to navigate, communicate and look out of the cockpit for situational awareness.

REGENT Craft had to work hard to attract top talent to join its team in Rhode Island, the smallest state in the United States that is also known for a strong maritime heritage and its approximately 400-mile (644-kilometer) coastline with large bays and inlets.

"And something I'm really proud of as a co-founder is the team that we've built here that spans some of the best boat builders on the planet that are designing and building America's Cup and SailGP racing yachts with some of best aerospace engineers on the planet who have designed electric aircraft and brought aircraft into production and certified them, combined with engineers and manufacturers from the EV (electric vehicles) space who have scaled automotive and battery production. Combined with some of the greatest software engineers on the planet who are designing our software and control systems on multiple vehicles, including spacecrafts," Thalheimer said.

The result is a vessel regulated under shipping law in the United States and the International Maritime Organization internationally.

The seaglider can travel 180 miles at 180 miles an hour, or 300 kilometers at 300 kilometers an hour, making it possible to do missions that last an hour on battery power – tapping seven Tesla’s worth of batteries on board.

The vessel operates in waves up to five feet for both take offs and landings, making it ideal for routes connecting coastal destinations as well as over-water routes linking islands.

That coastal passenger and cargo market, accounting for about 40 percent of the world’s population, represents a $600 billion opportunity for seagliders, Thalheimer said.

That has generated an “explosive growth” of REGENT Craft’s backlog and interest in seagliders all around the world, with more than $10 billion in commercial orders for the 12 passenger Viceroy seaglider that's currently undergoing testing and the 100-passenger Monarch version that is under development, Thalheimer said.

The technology has also attracted the interest of militaries around the world, leading to the recent launch of REGENT Defense as the company looks to develop seagliders into a logistics platform, accessing areas with limited infrastructure and medical evacuation vessel capable of operating in conditions that are hostile to seaplanes.

The U.S. Marine Corps has a $15 million contract with the company.

REGENT Craft plans to use the same model for both civilian and defense customers, with the military version expanding into hybrid and autonomy form factors.

Defense customers look to use seagliders as island-hopping machines for moving troops and supplies in places like the Indo-Pacific, where there is significant geopolitical tension between China, the U.S., and its allies in the region.

REGENT Craft has benefitted from advances made by developers of electric aircraft and electric vehicles who pushed battery systems developments and set up intricate supply chains.

"In less than five years, we have our full-scale prototype on the water with safety systems sufficient to take on human crew. I mean, literally myself was on that seaglider earlier today, and we are imminent, within a couple of years now, of our first deliveries to both commercial and defense customers. 2027 seagliders will be in operation in multiple places in the world," Thalheimer said.