Why aren’t we using ground-effect airplanes in Ocean travel

Question

If ground effect are so much more efficient why aren’t we using them for flights, from Europe to the US for example?

In: Engineering

Answer 1

For the ground effect to have substantial effect, you need to be close to the surface. Like, 20%-of-the-wingspan close to the surface. That’s 40 feet for a 747. A quick Google says ocean swells average 11 feet. That’s a quarter of the distance available. A couple waves meet in front of your flight path and you’re slamming an aluminum can into a brick wall at 500mph.