REGENT Viceroy Seaglider Completes Crewed Hydrofoil Trials in 2025

REGENT’s Seaglider Hydrofoil Breakthrough: Advancing Electric Maritime Aviation Toward Commercial Reality

REGENT Craft’s successful crewed hydrofoil trials with its Viceroy seaglider prototype mark a pivotal leap in electric maritime aviation, positioning the Rhode Island-based company at the forefront of coastal transportation innovation. Achieved in late June 2025, this milestone is the second of three critical operational modes, following float trials and preceding flight testing, required for the world’s first passenger-carrying seaglider to enter commercial service. With a global order book exceeding $9 billion and a clear regulatory pathway via maritime authorities, REGENT’s approach to ground-effect flight promises to transform regional mobility by merging the speed of aircraft with the convenience and regulatory simplicity of maritime vessels.

The Viceroy seaglider’s recent hydrofoil trials not only validate its technical design but also signal a new era for sustainable, high-speed coastal travel. As battery technology and regulatory frameworks evolve, REGENT’s success may serve as a blueprint for future Electric-Aviation solutions, with implications for both economic development and environmental stewardship.

Revolutionary Technology Foundation and Company Genesis

REGENT Craft was founded in 2020 by Billy Thalheimer and Mike Klinker, both MIT-trained aerospace engineers with backgrounds at Aurora Flight Sciences, a Boeing subsidiary. Their vision was to address the limitations of electric aviation, particularly range constraints imposed by current battery technology, by developing a hybrid maritime-aviation vehicle. The result is the seaglider, a ground-effect craft that leverages the physics of flying close to the water’s surface to maximize efficiency.

The core principle behind the seaglider is ground effect: when an aircraft flies within one wingspan of a surface, it benefits from increased lift and reduced drag, effectively doubling the range compared to conventional electric aircraft at higher altitudes. The Viceroy seaglider operates in three modes: floating like a boat, hydrofoiling above the waves for efficient surface transit, and flying in ground effect within 65 feet of the water’s surface. This tri-modal operation is made possible by a team combining aerospace and marine engineering expertise, resulting in a vessel designed from the ground up for maritime environments.

Unlike traditional seaplanes, which are essentially aircraft with floats, the Viceroy is engineered as a maritime vessel with integrated flight capabilities. Its deep V-shaped hull and retractable hydrofoils are optimized for smooth transitions between modes, and its control systems are tailored for both water and air operations. This design philosophy is a direct response to the shortcomings of earlier ground-effect vehicles, such as the Soviet-era ekranoplans, which lacked wave tolerance and maneuverability.

Breakthrough Hydrofoil Testing Achievement

The June 2025 hydrofoil trials in Narragansett Bay validated the Viceroy’s ability to transition from hull-based operation to hydrofoil mode, lifting its 15,000-pound mass above the water on retractable foils. This followed initial float-mode testing in March 2025, where the prototype, dubbed “Paladin,” first entered the water with a crew. During hydrofoil trials, the Viceroy accelerated on its hull, rose onto its foils, maintained stable flight above the surface, and then returned to hull mode, demonstrating the seamless integration of maritime and aerospace technologies.

Co-founder and CTO Mike Klinker described the experience as “surreal,” emphasizing its significance as a milestone for both REGENT and the broader field of electric maritime aviation. The hydrofoil system addresses historical limitations of ground-effect vehicles by enabling stable, efficient operation in varying sea conditions, targeting speeds up to 50 knots, about double that of conventional production hydrofoils.

The successful hydrofoil trials also highlight the practical benefits of this intermediate mode: improved maneuverability, smoother handling in rough seas, and enhanced passenger comfort. These factors are essential for commercial viability and set the stage for the final phase of testing, full ground-effect flight.

“This is a major milestone and a powerful validation of the years of innovation, grit, and world-class engineering our team has poured into this vision.” — Billy Thalheimer, REGENT CEO

Technical Specifications and Operational Capabilities

The Viceroy seaglider is a 55-foot-long vehicle with a 65-foot wingspan, designed to carry 12 passengers or 3,500 pounds of cargo, with a maximum takeoff weight of 15,400 pounds. Its propulsion system employs 12 electric motors (six per wing) powered by advanced batteries, enabling a range of 180 miles with current technology. REGENT anticipates that future battery advancements could extend this range to 400–500 miles.

In ground-effect flight, the Viceroy can reach speeds of up to 180 mph, while its hydrofoil mode targets 50 knots. The low-altitude flight envelope (within one wingspan of the water) not only boosts aerodynamic efficiency but also ensures compatibility with maritime traffic and infrastructure. The composite-intensive construction, in partnership with Moore Brothers Co., provides the necessary structural integrity while minimizing weight.

Advanced control systems enable seamless transitions between float, foil, and fly modes, a capability that distinguishes the Viceroy from previous attempts at ground-effect vehicles. Months of rigorous subsystem testing, including motors, batteries, electronics, and control software, preceded the crewed trials, reflecting REGENT’s commitment to safety and reliability.

Market Demand and Commercial Financial Outlook

REGENT’s market traction is substantial, with over $9 billion in global Orders from more than 600 customers spanning six continents. This demand comes from Airlines, ferry operators, freight companies, and leasing organizations, illustrating the broad appeal of the seaglider concept. Notable customers include Mesa Airlines, Mokulele Airlines, Southern Airways Express, Brittany Ferries, and FRS.

Southern Airways, operating under the Mokulele Airlines brand, is slated to be the first commercial operator, aiming to reduce inter-island travel costs in Hawaii significantly. UrbanLink Air Mobility recently increased its Viceroy order to 47 units, further signaling market confidence. Internationally, New Zealand’s Ocean Flyer and a joint venture in the UAE with Strategic Development Fund highlight the global reach.

REGENT has raised over $100 million in investment from Founders Fund, Lockheed Martin, Japan Airlines Innovation Fund, Hawaiian Airlines, and others. The company projects an $11 billion addressable market, potentially expanding to $25 billion as battery technology improves. The economic case extends beyond passenger transport to include cargo, emergency response, and defense applications, with the U.S. Marine Corps already partnering for logistics and search and rescue missions.

“86% of coastal residents would be interested in using seagliders for regional coastal travel.” — REGENT global survey

Regulatory Framework and Certification Pathway

One of REGENT’s key advantages is its regulatory strategy. The Viceroy qualifies as a Type A Wing-In-Ground Effect (WIG) craft under International Maritime Organization guidelines, allowing it to be certified by maritime authorities rather than aviation agencies. In the U.S., the Coast Guard oversees certification, and REGENT submitted its Design Basis Agreement (DBA) in March 2025, outlining how the seaglider meets safety standards equivalent to traditional vessels.

The Coast Guard’s approval of the DBA, expected by mid-2025, will allow REGENT to proceed to the final design and inspection phase. Recent federal legislation also requires the FAA and Coast Guard to clarify their roles regarding WIG vehicles, potentially streamlining regulatory oversight. For international operations, REGENT has partnered with Lloyd’s Register to ensure compliance with regional maritime authorities.

Maritime regulation offers more flexibility and lower costs compared to aviation certification, focusing on structural soundness, technical standards, and equipment requirements. This pathway is essential for the economic viability of seagliders, enabling faster deployment and broader market access.

Manufacturing Infrastructure and Production Timeline

REGENT is building a 255,000-square-foot manufacturing facility at Quonset Business Park in North Kingstown, Rhode Island, scheduled to be operational by mid-2026. This site will handle component manufacturing, final assembly, and pre-delivery testing, leveraging Rhode Island’s maritime composites expertise and coastal testing environments.

The facility is expected to create 300 jobs initially, with the potential to grow to 750 over the next decade, supported by state incentives totaling up to $17 million. Its location near established defense and marine manufacturers provides access to a skilled workforce and specialized suppliers.

Internationally, a joint venture with Abu Dhabi’s Strategic Development Fund will establish manufacturing, maintenance, and training capabilities in the UAE, supporting Middle East operations and expanding REGENT’s global footprint. First Viceroy deliveries are targeted for 2026–2027, with Mokulele Airlines expected to be the launch operator.

Industry Context and Future Outlook

REGENT’s seaglider development is part of a broader movement toward electric aviation and sustainable transportation. Unlike most advanced air mobility initiatives focused on urban environments, REGENT addresses coastal markets, leveraging existing maritime infrastructure and regulatory pathways. Its technical approach overcomes the range limitations of battery-powered aircraft and the operational shortcomings of historic ground-effect vehicles.

Strategic Partnerships with airlines and ferry operators, along with strong backing from aerospace and transportation investors, validate REGENT’s market positioning. As battery technology advances and regulatory clarity improves, the company is poised to scale operations both domestically and internationally.

The economic and technological ripple effects of REGENT’s success could establish Rhode Island as a global hub for the blue economy, attract further investment, and serve as a model for sustainable regional transportation worldwide.

“REGENT is a true Rhode Island success story and a cornerstone of our state’s blue economy future.” — K. Joseph Shekarchi, Rhode Island House Speaker

Conclusion

REGENT’s hydrofoil trials mark a watershed moment for electric maritime aviation, validating the technical and commercial viability of the seaglider platform. With regulatory approval on the horizon, a robust manufacturing pipeline, and strong market demand, REGENT is on track to launch commercial operations by mid-decade. The company’s integrated approach, melding aerospace and maritime technologies, has overcome historical barriers and set a new standard for innovation in coastal transportation.

Looking ahead, continued advancements in battery technology, regulatory frameworks, and international partnerships will shape the seaglider’s trajectory. As REGENT moves toward flight testing and commercial deployment, its achievements may not only redefine coastal mobility but also catalyze broader shifts toward sustainable, high-speed regional travel.

FAQ

What is a seaglider?
A seaglider is an electric ground-effect vehicle that operates over water in three modes: floating, hydrofoiling, and flying close to the water’s surface, combining features of boats and aircraft.

How fast and how far can the Viceroy seaglider travel?
The Viceroy can reach speeds up to 180 mph in flight mode and 50 knots in hydrofoil mode, with a current range of 180 miles, expected to increase as battery technology advances.

How is the seaglider regulated?
The Viceroy is certified as a maritime vessel (Type A WIG craft) by the U.S. Coast Guard and other maritime authorities, not by aviation regulators, allowing for a more streamlined and cost-effective certification process.

When will commercial operations begin?
Commercial deliveries are targeted for 2026–2027, with Mokulele Airlines in Hawaii expected to be the first operator.

What markets are targeted for seaglider deployment?
REGENT’s initial markets include coastal passenger transport, cargo, emergency response, and defense, with customers and partners across North America, Europe, the Middle East, and Oceania.

Sources: Aviation Week, Regent