Boston-based company Regent has taken US$465 million in pre-orders for its super-fast electric "Seaglider." Using the wing-in-ground effect, this 180-mph (290-km/h) beast promises twice the range of an electric aircraft, and a revolution in coastal transport.
"The speed, comfort, and navigation systems of an aircraft with the convenience, maneuverability, and affordability of a boat," reads the Regent press release, marking approximately the first time boats have ever been called affordable or maneuverable.
So, what is this thing? Well, it's the latest incarnation of a ground-effect vehicle, or GEV – with a couple of twists. GEVs are aircraft designed to fly so low (within one wingspan of the water's surface) that they ride on an air pressure cushion between the wing and the surface, giving them extra lift and radically boosting their efficiency. They can't – or at least, don't – fly outside the ground effect, enabling them to be certified and registered as boats in certain areas.
There have been several iterations of this idea since the 1960s. The most famous GEV is likely the giant Soviet Ekranoplan, capable of lifting 600 tons of cargo and hitting speeds up to 310 mph (500 km/h). Things have been a lot more humble in recent years; in 2018 we wrote about Singapore's reverse delta-winged Wigetworks Airfish-8, which is already up and running. But Regent adds some new elements to the mix.
For starters, it's fully electric and zero-emissions. This is not just significant because of the clean transport angle, or the reduced pricing it should offer thanks to cheap energy and low maintenance. Its high efficiency and lack of need for aircraft levels of reserve power give it the ability to extract twice the range from a given size battery as an electric plane – the initial Seaglider promises 180 miles (290 km) at 180 mph. So, while its use will be limited to travel between coastal areas, it should be able to join dots that clean conventional aircraft can't.
Secondly, it adds a little extra comfort and efficiency in the takeoff and landing phases, since it rises out of the water on a hydrofoil before taking off on the wing. At speeds between 20 and 45 mph (32 and 72 km/h), Regent's machine will be up on its foil, radically reducing drag against the water and smoothly sliding over the top of waves where something like the Airfish might get a much bumpier ride.
Regent says it's "received $465M in provisional orders from some of the world’s largest airlines and ferry companies. Aircraft operators are excited because seagliders are half the operating cost of aircraft, and ferry operators are excited because the seagliders are six times faster." They can operate from existing docks, and passengers will get much more of a marine-style experience than the indignities foist upon them at an airport.
Streaking along the surface of the water at three times highway speed will also offer a thrill, although GEVs this quick will certainly add an element of excitement to marine traffic sharing the same waters. They won't be particularly quick to turn at that speed, and your average group of fishermen six beers into their afternoon can be forgiven for not seeing this thing coming and turning across its path. Some floppy hats are going to get blown off.
Regent appears to have some solid investment behind it as well, with Mark Cuban, Thiel Capital, Y Combinator and Caffeinated Capital on board, among others. It has not yet named the pre-sale customers, or put forward an expected timeline for prototyping, testing, production or entry into service, so presumably it'll be a good while before we're taking our first rides.
This kind of technology could be of interest far beyond this kind of eight-to-10-seat coastal mid-range transport. The Soviet Ekranoplan program demonstrated that GEVs can become increasingly efficient with scale, opening up the potential for longer-range, higher-speed electric ocean liners carrying hundreds or even thousands of passengers. With range looking like an insurmountable barrier for battery-electric intercontinental airliners, perhaps the ground effect may yet have a chance to change the world.
Check out a video below.
Source: Regent
If you're limited to one wing length above the waves and speeds under 200 mph, that probably means no flying in anything where wave heights are more than 1/4-1/3 of wing length. And probably wind speeds less than 30-40 kt. Otherwise there might be excessive, um, excursions in airspeed and altitude.
First it needs a low wing so you can fly 8' higher on the same power or the same height on less
power.
If designed correctly the wings will raise the boat before the hydrofoil would take effect making it moot.
The hull is too sharp/deep V and will dig into the water. A 30Deg deadrise would be much better.
GEC chord is much more valuable than wingspan as you get lift from the trapped bubble of air under the wing. A long fore and aft wing length holds that bubble better.