Regent and the electric seaglider betting that the fastest way over water flies a few feet above it

Regent, a Rhode Island company founded in 2021, is building an all-electric “seaglider” called the Viceroy that carries twelve passengers across the water at roughly 180 mph (about 155 knots) while flying just a few feet above the waves. It is neither a boat nor an airplane but a deliberate hybrid that lives permanently inside ground effect, and as of 2024 the company has flown a full-scale, crewed prototype in Narragansett Bay. The concept is built on nearly century-old physics, but real engineering and regulatory hurdles still separate it from a fleet in daily service.

What Is a Seaglider?

A seaglider is a vehicle designed to fly continuously within ground effect—the cushion of high-pressure air that forms when a wing operates within roughly one wingspan of a surface.

Every pilot has felt this. On short final, you cross the threshold, flare, and the airplane simply refuses to quit flying. It floats on a cushion. That cushion is real: close to the ground, the wingtip vortices get squashed, induced drag drops, and the wing becomes dramatically more efficient.

Most pilots treat ground effect as a nuisance to manage on landing, or a trap that bites you on a soft-field takeoff. Regent’s engineers asked the opposite question: what if you designed a vehicle to live inside ground effect permanently?

The Ekranoplan: The Soviet Machines That Came First

This idea is not new. Starting in the 1960s, Soviet engineers built ground-effect vehicles called ekranoplans.

The most famous, the Lun-class, was the size of an airliner, weighed close to 400 tons, carried eight jet engines mounted near the nose, and skimmed across the Caspian Sea at roughly 300 knots, just ten to fifteen feet off the water. American spy satellites spotted these machines and analysts genuinely could not classify them—a ship that fast and an airplane that big and low both made no sense. The press nicknamed one the “Caspian Sea Monster.”

The ekranoplan worked. It moved enormous loads fast and efficiently by trapping itself in ground effect over flat water. The reason you have never ridden in one comes down to a few brutal problems—and those same problems are exactly what Regent claims to have solved.

Why a Seaglider Could Beat the Ferry

Over water, a wing in ground effect is wildly efficient, combining the smoothness of low flight with the speed of actual flying.

A fast ferry does maybe 40 knots and beats you up the whole way in any sea state. The Viceroy targets roughly four times that speed, while being quieter and producing zero direct emissions because it is fully battery-electric.

The efficiency is what makes electric power viable here. Batteries are heavy and store a fraction of the energy of the same weight of jet fuel—the density wall every electric aircraft program hits. The seaglider’s answer is clever: don’t fight to climb and cruise at altitude where flight is expensive. Stay low, stay in the cushion, and let the physics carry the cost.

How Does the Viceroy Handle Waves?

Waves are the central problem. A runway holds still; an ocean heaving in six-foot swells does not. The old ekranoplans were dangerous in anything but calm water and demanded enormous pilot skill to avoid clipping a wave and cartwheeling—a wingtip touching water at 150 knots is not a fender bender.

Regent’s answer is the most interesting engineering decision in the program: a retractable hydrofoil system. The Viceroy operates in three distinct modes:

• Floating — Leaving the dock, it sits on its hull like an ordinary boat. Low speed, fully maneuverable, operating straight out of an existing harbor with no runway or airport required.
• Foiling — As it accelerates, retractable hydrofoils extend beneath the hull and lift the whole vehicle clear of the chop. This smooths the ride and, critically, carries it up and over the rough water near shore—the exact place a low-flying machine is most vulnerable.
• Flying — Once it is foiling fast enough and out past harbor traffic, it retracts the foils, lifts off, and settles into ground-effect flight a few feet above the surface for the cruise.

The hydrofoil is the safety bridge. It gets the vehicle from a standstill at a crowded dock up to flight speed without ever risking contact between a fast-moving wing and a wave—the failure mode that haunted the Soviets. In rough conditions, the foils also raise the sea state the vehicle can handle.

Why It’s Regulated as a Boat, Not an Airplane

Because the seaglider stays within roughly a wingspan of the surface, international maritime rules classify it as a vessel, not an aircraft. Regent’s primary regulator is therefore the U.S. Coast Guard, not the FAA.

That is a genuine advantage. The Coast Guard certification path for a novel marine vessel is more achievable in the near term than certifying a brand-new category of crewed aircraft. eVTOL air-taxi startups have ground through years of FAA rulemaking just to define what the rules are; Regent sidesteps much of that by being, legally, a fast boat.

The caveat is honest: being a boat means operating in marine traffic, under marine right-of-way rules, in shared waterways near other vessels, swimmers, and harbor traffic. A 150-knot object operating low over a busy harbor is a genuinely new safety question, and harbor authorities will have opinions. The path is more defined than the air-taxi world—but it is not free, and it is not finished.

How Far Can It Actually Go?

The Viceroy’s target range on today’s batteries is on the order of 180 miles. That is a real, useful number—Boston to Provincetown, the Hawaiian island hop, ferry routes in the Gulf, the Pacific Northwest, the Greek islands, coastal-city connections where today you take a slow ferry or drive hours around the water.

But notice what that range is not. It is not transoceanic, and not even most over-water trips a regional airline flies. The seaglider is a coastal and inter-island machine, full stop. Longer ranges wait on better batteries—the same story as the rest of electric aviation. Anyone calling this “the future of flight” should pump the brakes; it is the future of a specific, water-bound slice of transportation.

Is This Real, or Just a Render?

Regent was founded in 2021 by two MIT aerospace engineers, Billy Thalheimer and Mike Klinker, and is based in North Kingstown, Rhode Island.

What separates them from pretty animations is flown hardware. They built and flew a quarter-scale prototype, then a full-scale, human-carrying Viceroy, and in 2024 began on-water testing with people aboard, running the float-foil-fly sequence in Narragansett Bay. A flying, crewed, full-size prototype is meaningfully different from a press release.

On the order book, Regent has announced a backlog of well over 600 seagliders from operators and defense customers interested in runway-free coastal logistics; Mokulele and other regional operators have been named. Whether those commitments convert into delivered, revenue-flying vehicles is the open question. Letters of intent are cheap; type-certified, insured, paying service is expensive and slow.

Why This Matters for Pilots

The seaglider is one of the more intellectually honest ideas in the electric-transportation push because it doesn’t pretend batteries are something they’re not. Instead of demanding a better energy source, it changed the problem to fit the energy source we already have—good engineering that solves a real problem instead of waiting on a miracle.

For pilots, it is also a vivid lesson in the aerodynamics you already feel from the left seat. Ground effect is not just a landing nuisance; harnessed deliberately and paired with hydrofoils, it becomes the entire operating principle of a new class of vehicle.

The honest scorecard: the physics is sound and almost 100 years old; the infrastructure story is strong because it uses existing docks; the Coast Guard path is more concrete than the air-taxi route; and real crewed hardware is flying. Against that, sea state remains the hard limit, range is modest and battery-bound, operating a fast low machine in crowded waterways is unsolved, and the gap between a flying prototype and a certified fleet is measured in years, not months.

Key Takeaways

• Regent’s Viceroy is an all-electric, 12-passenger seaglider targeting 180 mph cruise while flying a few feet above the water in ground effect—roughly four times faster than a ferry.
• It operates in three modes—float, foil, and fly—using retractable hydrofoils as a safety bridge to avoid the wave-strike failures that doomed Soviet ekranoplans.
• Because it stays in ground effect, it is regulated by the U.S. Coast Guard as a vessel, a faster certification path than the FAA’s for novel aircraft.
• Range is currently about 180 miles, making it a coastal and inter-island machine—not a transoceanic one—until battery density improves.
• Regent has flown a full-scale crewed prototype (on-water testing began in 2024) and claims a backlog of 600+ orders, but a certified fleet in daily service is still years away.