No loophole nor exceptions - we're following guidance from the International Maritime Organization on the maritime regulation of Type A WIGs (
https://wwwcdn.imo.org/localresources/en/OurWork/Safety/Docu...), which have been upheld by flag states all around the world.
The benefit of ground effects are:
- 10-20% range extension (agreed, between 50% and 100% wingspan, which is where seagliders fly, the aerodynamic benefit of ground effect is reduced compared to near surface flight)
- Drastic reduction in reserve fuel. This is a key limitation of electric aircraft because they need to sustain powered flight to another airport in the event of an emergency. We can always land on the water, therefore, we can count all of our batteries towards "mission useable"
These two effects combine to give seagliders double the range of any electric aircraft - 180 miles with existing battery technology.
We use hydrofoils to solve for the wave tolerance and maneuverability problems that plagued past WIGs and made them commercially unviable. To take-off directly from hydrofoils before they cavitate, we had to slow take-off speed to ~50 mph, which drove us to a "blown wing" design that distributes propulsion over the wing, "blowing" the wing with high speed air and therefore creating high lift even at low speeds.
Very difficult to distribute propulsion with IC engines or mechanical linkages. Electric propulsion technology unlocks the blown wing, which unlocks the use of hydrofoils, which unlocks wave tolerance and therefore operations of WIGs, which unlocks longer range of electric flight. It all works together.
And electrification is generally good: both for the planet and for ticket prices