Popular Mechanics: Piloting a Hovercraft

I’m 30 seconds into my first hovercraft solo when things start to go wrong. Zipping along near a sandbar in the middle of the Wisconsin River, I’m cranking around into my first turn and I find myself gradually losing speed.

Soon I’m dead in the water. I gun the throttle. The engine screams, and water sprays up over the gunwales in sheets. It’s like sitting in a car wash, one that’s getting carried away downstream. I turn the handlebars this way and that, but the only thing that changes is the direction of the drenching. All I can do is open the throttle all the way and aim toward the sandbar. Crawling along, I pay for each inch of progress with a bucketful of spray. At last, I reach terra firma. Never before have I been so soaked and so relieved.

“Okay,” says my instructor, Bill Zang, who’s been watching from land. “There’s something I need to tell you about how this works.”

Zang, the president of Universal­ Hovercraft, has invited me to come along and take part in a great but underappreciated ritual: the summertime hovercraft rally. On any given weekend somewhere in the U.S., bands of devotees gather on the shores of an inland waterway to zoom around, barbecue, and talk shop. On this particular Saturday, the clan has assembled in Muscoda, Wisc., a rural village an hour west of Madison. As the morning gets underway, a dozen or so ­vehicles are drawn up on and around the boat ramp. Almost all are homemade, and while their appearance ranges from amateur to sleek, all share an ineffable brand of anachronistic glamour.

When the hovercraft was invented in the 1950s, it seemed an exciting vision of a future where vehicles would float through the air. So far, the 21st century remains flying-car-free, but a small yet passionate tribe is keeping the dream alive. For them, this technology is a sleeper just waiting to catch on. “The great thing about hovercraft,” Zang’s uncle John Windt, himself a hovercraft builder and pilot, points out, “is that you can go anywhere.”

True enough, a hovercraft doesn’t rest on the surface, so it can go places no other vehicle can, like over shallow water, thin ice, or deep mud—any surface, really, as long as it’s reasonably flat. The essential fascination, though, has nothing to do with practicality. It’s that magical feat of being suspended in air, which still seems impossible even when you know the physics behind it.

The key component is a horizontal ducted fan that blows air underneath the hull. A flexible skirt around the edge keeps the air from dissipating too quickly, so a bubble of high pressure forms and lifts the craft. A second ducted fan provides horizontal thrust to push the hovercraft over the surface, with vanes to allow the thrust to be diverted side to side for turning.

Though the principle is simple, conventional hovercraft can be complex to operate and maintain, limiting their appeal for the public. That reality has led Universal Hovercraft to develop a smaller, simpler model called the Renegade. Instead of two engines it’s got just one, as well as a tough, lightweight body made of Kevlar and carbon fiber. With handlebars and a bench seat, it looks like a Jet Ski from the floorboards up.

As I fight my way to shore, though, I’m having my doubts. But after I towel off, Zang explains that my problem is minor. When I came to a stop, he says, the skirt filled with water and weighed down the machine. If that happens again, I can drain the skirt and get up to speed by shifting my weight forward while gunning the engine. I try again, and after 30 seconds I’m stalled and sopping wet again. But I keep at it, and eventually the penny drops: It’s counterintuitive, but the direction in which you’re pointing a hovercraft has nothing to do with the direction in which you’re going. What you have to do is start a turn, then immediately turn against it so that your velocity vector doesn’t change too quickly.

Ten minutes in, I’ve got it. I glide across the river, careening this way and that as if I’m riding on that spaceship in the old video game Asteroids. I keep track of three different vectors: my thrust, my velocity, and where I’m pointing. To make a turn without hitting things, you’ve got to plan ahead, and even then I find myself whacking through some overhanging branches from time to time.

It’s a perfect early summer day, and it doesn’t take long for the boat ramp to empty out. Some head out on daylong expeditions, while others find a secluded island and pitch tents. With Zang’s voice in my ear via radio headphone, I go chasing up the river after his uncle’s homebuilt machine as he heads up the Wisconsin. Along this stretch, shallow water and innumerable obstacles make the river all but unnavigable for conventional boats. Except for a few canoeists, we have the whole waterway to ourselves. We skirt the forested banks, circle tiny islands, dart through narrow channels, and zoom over sandbars like a pair of air-hockey pucks. I grew up around motorboats, so I find it deliciously liberating to accelerate toward land and just ride right over it.

As the sun slides toward the horizon the wind fades, leaving the river glassy. Brown sandbars swirl under its surface like brushstrokes. The forest canopies on either side turn misty and shrouded in the declining light while we twist in big, lazy S turns. I pass a barn, a lakeside house, the curve of a sandy riverbank. I’m racing through an astonishingly beautiful corner of America, seeing it in a way I’ve never experienced before: sideways.

This post went live on PopularMechanics.com on March 5, 2014. Read the original here.