TL;DR: While faster and more fuel-efficient than regular ships, they're as complicated and fragile as airplanes. And since they can't fly, they're at risk from waves and colliding into land or other ships.
The AirFish is a smaller version of this. The cupped shape of its wings does not appear to have curves, which means it will crease like oragami (welded sheet metal sections?)
Since the in-ground effect is limited to a couple dozen feet - this craft is compatible only with the calm waters of a bay/lake/river. Maybe shorelines, but large breaking swells would be rough for the small, personal vessel anyways. That is why it's safe - unleaded gasoline spinning a prop with similar horsepower of a V8 barely suspended above the low friction and cushion
of flat water. An error (equipment or operator) would occur at low altitude and the optimum resolution would be to skid-to-a-float (last resort safety measure is to guarantee the nose is up at sufficient angle because the marine body is both landing gear and airbag in a sense).
Could the wing sections fold along the creases and temporarily adopt a more aero dynamic configuration in order to "leap" across impediments to a smooth surface? Flat land could also be a surface off of which a fuselage could propel itself via in-ground effect wingspan geometry, in which case "roads" would only need to be relatively flat and straight "lanes" with wingspan accommodation. Impact buffer would be suspension and durable tires (along with similar software interventions - "if impact imminent then nose up to skid instead of tumble") instead of sufficiently deep water and a marine body.
So long as the vast locale requiring traversal is barren terrain with no vegetation and a sufficient gaseous atmosphere medium for in-ground-effect air cushion (would not work in vacuum).
Depending on the local gravity well strength (variable per hosting body), a V2 engine horsepower equivalent may perform the same amount of work.
But would atmospheric pressure at ground level make a difference if we are trying to "ride the cushion" that exists because of sea level atmospheric pressure of the planet in the AirFish YouTube video?
I find myself wondering if those risks couldn't be managed by modern technology. Check the water surface and adjust.
Also, I believe altitude above the ground depends on the size of the wings, so with much larger wings, they might be able to fly high enough to clear more obstacles.
The Lun was heavily armed, and NATO considered it a super fast patrol boat. The soviets really doubled down on missile boats.
The range of the Lun’s missiles out ranged its radar, which was a problem that missile boats of that era also had. Nato imagined that a forward Lun would act as scout for the rest etc with lots of coordination.
The Lun’s problem was that by the time it entered trials the soviet missile boats were being fitted with a over horizon radar that the Lun couldn’t carry.
That, and the end of the Cold War, of course.
The coordination idea is interesting; the last generation of soviet “carrier killing” anti-ship missiles were designed to do coordinated attacks where one missile would pop up to identify and allocate targets to its cohorts staying down low. If it was intercepted, another of the low missiles would then go high and so on. https://en.m.wikipedia.org/wiki/P-700_Granit
Of course for missile coordination to work like that, the launcher has to know there is something to fire at in the first place...
One of the main reasons why the project was abandoned was the immense difficulty of controlling it, especially in huge seas.
I wonder if a similar vehicle would have advantages over conventional ferries and freighters today, given the advancements in electronics and assisted steering.
Ekranoplans were high-maintenance, sucked corrosive saltwater into the engines, had huge turning radiuses and couldn't operate in rough waters. Mustard did a great video on why they failed: https://www.youtube.com/watch?v=yVdH_dYlVB8
Gotta imagine the margin for error within a ground effect envelope is ULTRA thin. A plane loses a little altitude so what, catch a wave ... I can imagine that's not good.
Not just one of them the same one that is referenced in the Wikipedia entry. The wikipedia article says it was towed and Popular Mechanics said it broke free of its oppressors and headed for a nearby beach :-)
Timely in this age of massive forest fires. The engines are made in Ukraine though, so don't know if it's deliverable in the current geopolitical situation.
https://en.wikipedia.org/wiki/Ground-effect_vehicle
TL;DR: While faster and more fuel-efficient than regular ships, they're as complicated and fragile as airplanes. And since they can't fly, they're at risk from waves and colliding into land or other ships.
Here's another fascinating prototype: https://en.wikipedia.org/wiki/Bartini_Beriev_VVA-14