There was a chap next to the boating arena with a couple of Ekranoplan or Wing in Ground Effect (WIG) models. Not really boats and not really planes, I love this concept.
The theory is that close to the ground you get the twice the lift for the same amount of drag. It has the pleasant side effect of giving an aircraft a gentle cushion as it comes into land. But if you have to cross a nice open space like, say, the sea..., you can design a machine that never gets very high, has small wings (even less profile drag) and is very efficient. Downside is that you need huge amounts of power to
get it out of the water and then you're left with extra weight from engines you don't need. Also, a bit like a hovercraft, you have to keep a good eye on the size of the waves you're flying just over the top of.
The Russians played about with the idea in the Eighties and created what became known as the Caspian Sea Monster, with ten (!) jet engines for takeoff, it cruised using only two.See here for more info:
http://www.se-technology.com/wig/index.php
