Startup Spotlight: Tidal Flight

Seaplanes have been around since the very early days of aviation, but their market success in recent years has been limited by an aging fleet of in-service aircraft that are relatively inefficient and inconvenient for many operators.

That may be starting to change. The explosion of interest around advanced air mobility (AAM) since Uber Elevate burst onto the scene nearly a decade ago has spurred new interest in electrifying seaplanes. The general thesis is that lower operating and maintenance costs from electrification, combined with improvements in hull design, can pave the way for a revival of coastal transportation that can provide for convenient point-to-point trips without the need for extensive infrastructure for passenger wait times.

The latest startup to officially throw its hat into the ring is Tidal Flight, which emerged from stealth last year, joining a growing wave of seaplane developers including Switzerland’s Jekta and Norway’s Elfly Group, while U.S. startups Regent and Sea Cheetah are developing wing-in-ground electric seagliders for coastal transport.

Founded by three Georgia Tech graduates who previously worked on flight sciences at Beta Technologies, the Hampton Roads, Virginia-based startup is planning to develop a nine-12 passenger hybrid-electric, amphibious seaplane called Polaris. With an maximum takeoff weight (MTOW) of 12,500 lb., the Polaris is being designed for an optimal mission of 100-500 mi. With a cruise speed of 162 kt. (186.4 mph) at 7,000-ft. altitude, the aircraft features a 59-ft. length and 59-ft. wingspan, and has the capability to transport a 3,100 lb. payload.

The company highlights its hybrid propulsion system as a key enabler for its aircraft. The system is a plug-in, series-parallel hybrid built around fuel-burning engines that burn Jet A, coupled with an electric motor and a sizable battery pack, both of which provide power to a pair of propellers mounted on a V-tail.

“We can control the power split between fuel-burning engines and the battery throughout the flight so we can go fully electric for takeoffs and landings and for harbor maneuvering, so that we can stay quiet close to communities but still get that extended range of burning jet fuel while cruising,” explains Mark Lau, co-founder and chief engineer at Tidal Flight. “Basically, the customer will have the ability to trade operating costs by using cheaper electricity with range by using Jet A-burning engines.”

Besides the hybrid propulsion system, Tidal Flight also highlights its hull design as a key breakthrough for making seaplanes more efficient. There is a much higher length-to-beam ratio hull than a traditional seaplane, which helps decrease its aerodynamic drag while improving impact loading when landing on water, explains Pranav Krishnamurthy, co-founder and chief technology officer at Tidal. He said the company is also exploring different hull shapes to get reduced aerodynamic drag during cruise while ensuring stability when lifting off from the water.

The Polaris design has already been validated during flight testing with a ⅙-scale prototype, which co-founder and CEO Jude Augustine said was intended to prove out the seaplane’s hydrodynamic performance during takeoff and landing.

The company has also conducted towing tank testing at the Stevens Institute of Technology’s Davidson Laboratory in Hoboken, New Jersey. As part of those tests, the seaplane’s hull was towed through a 300-ft.-long tank equipped with detailed instrumentation and sensors to validate the hull design and get a better understanding of flow dynamics.

“All this work has enabled us to both validate our initial hull design and drive the next iteration of that hull design,” Augustine says. “The combination of flight testing and tow tank testing is really what gives us that core confidence in our design.”

Tidal says it plans to build a full-scale powertrain testbed this year. Plans call for demonstrating the hybrid system on a full-scale prototype by mid-2027. The company aspires to certify the seaplane under FAA Part 23 in 2029, with first customer deliveries anticipated in 2030.

Tidal already has letters of intent for 100 preorders for the Polaris, valued at up to $650 million, with a diverse customer base including operators in North America and Southeast Asia. The latest conditional order was announced Feb. 11, with up to 20 aircraft ordered by Tropic Ocean Airways, a charter operator that plans to deploy the seaplanes in South Florida and the Bahamas.

The company is currently raising a seed round to finance development of the hybrid powertrain.

While the path to develop and certify an amphibious hybrid seaplane will pose many challenges, Tidal can count on guidance from experienced advisors. They include Dr. Brian German, who runs the Center for Urban and Regional Air Mobility at Georgia Tech, where the three founders met; Maj. Gen. (ret.) Eric Hill, who served as deputy commander of Air Force Special Operations Command and Augustine says will help drive contracts with the Defense Department; and Billy Nolen, the former acting FAA Administrator and current chief regulatory officer at Archer.