NORTH KINGSTOWN, RI—Regent Craft Inc. has conducted a successful test of its 12-passenger battery-powered Viceroy “seaglider” in Narragansett Bay. The 55-foot-long vehicle features a 65-foot wingspan and 12 electric motors.

The half boat/half plane seaglider is designed to fly five to 30 feet above the water and replace ferries and short-haul aircraft on coastal routes. It uses ground effect and dynamic soaring principles to ride on top of a cushion of air, resulting in 70 percent less drag than a normal plane.

Wing-in-ground effect is an aerodynamic principle that planes experience when flying close to the earth’s surface—either over solid surfaces or water. The phenomenon takes hold when operating within a distance of one wingspan from the surface.

According to Mike Klinker, chief technology officer at Regent Craft, the first on-water tests showcased “the successful technical validation of the novel maritime vessel with humans on board, marking a pivotal moment in transportation history.”

The sea trials followed months of rigorous subsystem testing of critical onboard systems, such as batteries, motors, electronics, controls and mechanical systems.

The high-speed vehicle, which is certified and regulated as a maritime vessel, operates exclusively over water in three modes: floating on the hull, foiling above the waves on hydrofoils and flying in ground effect mode near the surface of the water.

The four-year-old start-up company plans to start producing seagliders next year at a new 255,000-square-foot assembly plant in North Kingstown. Carbon-fiber composites components, such as the vessel’s hull/fuselage, will be made in Bristol RI, by Moore Brothers Co.

By the end of this decade, Regent Craft plans to produce a larger version of Viceroy dubbed Monarch. It will be capable of carrying 50 to 100 passengers.