WIGs

No, not the things you put on your head. I'm talking about Erkanoplans. What? Cross a hovercraft and airplane you get an erkanoplan or Wing In Ground effect (WIG) vehicle. The russians used them as high speed sea transports during the Cold War.

Wings have increased efficiency very close to the ground (or water). This has to do with wing-tip vortices. So if you stay in that region, you can "fly" across ground or water at low altitude very efficiently. Like a hovercraft except the air cushion the vehicle is created aerodynamically instead of with a fan.

The problem is that these vehicles can have some stability issues. Anyway I'd never heard of them before, but they are a neat idea I thought I would share.