This is the Yellow Jacket, a hovercraft that was featured in a Popular Mechanics article from March, 1971. You can go here to check out the article. The plans that people purchased from Popular Mechanics were actually somewhat diffrent than the original that was shown in the article, presumably to make it easier or cheaper to build.

I first heard about the Yellow Jacket when I was over at my dad's house for dinner. Apparently someone where he worked had seen it advertised for sale on craigslist, and they mentioned it to dad, along with a bunch of the other engineers. It looked pretty interesting, and it wasn't horribly expensive, so we thought we'd go take a look at it. It turned out to be owned by Kirk Swaney, the fellow that does the high-speed racing with electric cars. It was in far better shape than either of us thought it would be, and had all of the parts necessary to finish it. Besides which, it looked very cool and unusual. So I bought it. I was actually going to get married in several months, so I knew I wouldn't have much time to work on it for a while, but dad said he would take over the project.

When I bought it, it looked like this. No wonder I couldn't pass it up, no? Kirk had done a TON of research into the history of the thing, and had actually put together a website for it. Here is his website, telling the story of the craft before I got it. (Slightly edited to make it fit better with this site graphically).