THE WETBIKE IS GUARANTEED TO CROSS WATER WITH SOMETHING OF A SPLASH

One hot, dusty day in the summer of 1973, Nelson Tyler was tooling around the back trails of Lake Arrowhead, Calif. on a small motorcycle. As he neared his cabin, he had an insane urge to gun the bike, sail the length of his dock and shoot clear across the lake. He didn't. But the idea was planted. Within a few days Tyler got down to the serious business of inventing a motorcycle that would ride on water.

Tyler, an aeronautical engineer, was no idle dreamer. A few years before, he had come up with a funny-looking rig that, by eliminating all vibrations, allowed a cameraman to shoot perfect film from a helicopter. The Tyler Camera Mount is now a standard in the motion picture industry and has been used in hundreds of movies—among them, The Godfather, Catch 22 and Funny Girl. In 1971 it got Tyler an Academy Award for technical achievement.

Tyler's first water motorcycle took six months to build. It was a weird hybrid creature that looked like a motorcycle on top, but underneath it had wooden skis front and back and a propeller. It also didn't work. "On paper everything went like a charm," Tyler says, "but like the proverbial bump on a log, the bike just sat there." He tried a more powerful engine. He towed the bike behind a speedboat. He even considered lowering it from a helicopter. No matter what he did, the bike refused to rise out of the water.

A year and countless ski designs later (the skis are now made of aluminum and fiber glass), the water motorcycle was finally up and zooming along. It worked fine going straight ahead. Unfortunately, it was almost impossible to turn. And there was potential danger from the exposed propeller. So another year was spent perfecting a water-jet propulsion system that attached to the rear ski. After almost three years the Wetbike was finally ready.

And it is a marvel of design economy. There are no brakes, no clutch and no gearshift lever. The one-piece fiber-glass hull, which looks like a small rocket ship, does not contain a single bolt. Since the seat cushion lifts for direct access to the engine, repairs can be made without having to disengage any part of the body.

The rider straddles the machine like a bike, feet resting on pedals, and steers with handlebars connected to an independent front ski. At six feet from stem to stern and 300 pounds, it is about the size of an average motorcycle or snowmobile. It carries two riders comfortably. Its 65 hp, 816 cc. engine is comparable to a large racing bike's.

Recently, the Advanced Vehicle Research Corporation of Los Angeles (AVR), which is producing the Wetbike, invited professional motorcycle racer John Hately to test it out. Within minutes he had it jumping, balancing on one ski and executing interesting turns. However, not everyone should expect it to perform like a trained dolphin. The Wetbike is a new kind of vehicle, not to be confused with Ski-Craft, a power plant designed a decade ago to pull water skiers rapidly across the briny. The Wetbike requires practice—in some cases, lessons. First-timers should plan on taking from half an hour to a full afternoon just to get acquainted.

One mounts a Wetbike in about two feet of water. It's a good idea to have someone steady the bike, because it tips pretty easily. When idling, it floats partially submerged. As one gradually turns the throttle on the right handlebar, the bike begins to plow ahead with the hull still resting in the water. The Wetbike can be ridden comfortably at this slow speed, but what's the fun in that? If the rider continues to accelerate, at 10 miles an hour the bike suddenly rears up and leaps out of the water as if launched. By the time the rider has traveled 200 feet he is shooting along at 40 miles an hour, and on water this is an exhilarating speed. Except for the smack of the skis and a face full of spray, it's like going flat out on a Kawasaki 750.

There is one big Wetbike problem, though—turning. It is trickier than on a dirt bike and requires some strength and a lot of body English. At first try, the bike tends to kick away, leaving the rider in the drink. But when this happens, the bike automatically shuts off, submerges halfway, which brakes it, and rights itself. Remounting a Wetbike in water over your head is about as easy as riding a greased pig. One's tendency is to get on from one side and fall off the other. Beginners will do better to crouch on the back ski and leapfrog onto the seat.

AVR expects the first production models to be on the market next summer. The anticipated $1,900 price tag would be competitive with motorcycles of similar size. Tyler envisions Wetbikes pulling water skiers, jumping waves, racing, being used to explore otherwise inaccessible coves (they need only three inches of water when planing and can go almost anywhere), even aiding in law enforcement. He hopes a miniculture develops around his invention and insists it is safe for the whole family. When asked if his children ride the Wetbike, he answers, "Sure, I let them on it." Then he pauses and adds somewhat sheepishly, "but I follow them with a big boat."