You're screeching around the buoy course at 50 mph, slipping and sliding and having the time of your life. The goggles make you feel like a kid again, and the turquoise Bahamian water seems almost too perfect for the ride, like an animated backdrop. This Sea-Doo has all of the benefits of an interchangeable X-Box, including the soft, couch-potato seat in Kart mode. But there's nothing virtual about this reality. The taste of brine and the sun on your face is as real as it gets ' and so is the giddy feeling in your stomach as the 3D launches off a big wake and you tumble off, head-first into the ocean for a saltwater bath. Tilt. Game over. Hmmm ... switching channels to Vert mode.

Welcome to the wild, wacky world of the split-personality 3D. It's an offbeat idea for a watercraft, and initially you have trouble wrapping your arms around the concept of a 'totally new watercraft experience.' When words like 'watercraft revolution' and 'multiple experiences' are stressed, you're a little hesitant to believe in all the hype.

But once you ride the 3D, you realize it is all that and maybe even more. It's not quite a revolution for watercraft, but more like a missing link in the evolutionary development of the jet bike that delivers on the three 'experiences.'

Cutting through the jargon, the 3D uses a nimble-but-stable XP hull for its platform and has three quick-change configurations for the top ' Vert, which you ride as a standup; Moto, like a motorcycle; and Kart, for go-cart mode. The names sound a little hokey, like three magicians headlining a Vegas supper club. But, more importantly, the rides are solid and mostly live up to the hype. Two other things worth noting about the 3D: The low $6,999 base price, and that it's never boring. Three fun rides for the price of one.

Take Vert, for instance. Most standups require a minimal learning curve of a few hours, after which you still look like a drowned rat with throbbing thighs. On the 3D, you can stand up in the 26-inch-wide tray without the uneasy feeling like you're rolling on a barrel. Just hold the oversized handle pole, plant your feet almost anywhere you want on the neoprene floor, squeeze the trigger and go. True, the ride's a lot different than you'll get from a traditional standup, and you won't have the turn-on-a-dime responsiveness or prolonged air-time like on a Kawi 800 SXR, Yamaha Super Jet or 100-hp Polaris Octane.

But Vert's meant for those who'd rather ride a PWC than be dragged and still get the thrill and physical exertion of a standup. It's a blast on a buoy course, and once you get the basics, there's still an ample learning curve for mastering the XP hull in this standup mode. In Bimini, riders range from first-timers to former pro racers, and both get immediate gratification from Vert's stability.

Ah, there are some challenges. The newbies get up on the first try, but they hold on tight in waves and learn to shift their weight to steer through the tight turns. The pros look good in Vert mode but seem a little undersized in the super-sized craft, and they aren't cutting corners like they do on other standups.

Sea-Doo says Vert shouldn't be compared to other standups, since it's an entirely different animal, and likens the experience more to surfing, skateboarding or wakeboarding. Although some expert riders may miss the challenge of traditional standups, those riders who have enough experience to stay up on the traditional standup ' but still look like a person with rickets ' will find Vert to be just the ticket. It's a license to learn standup, without the learning curve.

Moto's also a trip to another dimension. Imagine sitting out on the water and thinking 'oh my, Vert's just a little boring today.' Flip a latch, and a narrow 26-inch-long switchblade seat drops down and snaps into a slot over the deck. Suddenly, you're knocking off buoys like a motocross racer leading the pack, riding so high off the water you can use that extra weight to get the 3D hull around turns. The experience is fundamentally different ' and for some, even more fun ' than Vert.

Again, direct comparisons are tough, but Moto reminds you of the Yamaha WaveBlaster or Sea-Doo HX. It has a dirt-bike feel, rather than the cruiser feel of a Harley. Add in the adjustable tilt-steering (it pivots 180 degrees into three positions, letting you use it as a trigger or thumb-squeeze throttle), red-marked slots for locking the seat into position, and even an optional seat cover with gel inserts, and you'll be jamming in the Moto zone until the 8.5-gallon fuel tank runs dry.

Like Vert, it's easy to start on Moto and it's hard to fall off ' unless you take a gamble and turn too sharply. Again, the challenge to master the machine and get the weight distribution right is there. Even the most advanced pros look a little shaky in high-speed turns. For many, Moto mode is the hands-down favorite.

But for you, the Oscar goes to Kart, arguably the most unique ride since Sea-Doo introduced the first sit-down jet bike in the '80s. It's a water-spanking, adrenaline-junkie's dream ride with the cushy seat that bolts into the neoprene floor (more like a boat's helm seat than the stiletto-like Moto seat) and foot inserts to keep you inside the craft. Kart mode feels like you're moving a lot faster than the 50-mph top end because you're nearly sitting on the water.

The power on this craft is a 782-cc Rotax twin-cylinder engine that generates 110 hp. This engine uses RFI, which isn't as fuel-efficient or emissions-friendly as Rotax's other Direct Fuel Injection or 4-stroke engines, but the engineers have found a nifty way to shut down one of the cylinders when the engine's idling, so it meets both EPA and CARB emissions regulations. Its water-jacketed dry exhaust system adds up to quieter running and prevents water from entering the engine if it's tipped over.

There are other noteworthy features on the 3D, especially given its low price. One is a manual trim on the nozzle that's easy to reach in the water; the other's an electronic off-throttle steering system. The 3D also has Sea-Doo's Digitally Encoded Security System for theft prevention. Options include custom covers, saddlebags and, alas, the Kart seat, which is an extra $599.

That's worth its weight in gold. While the other two modes are familiar in some ways, the Kart is definitely a breakthrough for watercraft technology. And more than the other experiences give you, Kart's just begging for a race on the water. And that's just what you do on the final day, a kind of 'Survivor' for wimps.

Teams of three ride each mode in sequence to beat the clock. You bring up the rear in Kart mode, and it's a flashback to junior high, where you're propelled around a figure-eight course on a go-cart with a Briggs & Stratton lawnmower engine at speeds that seem to rival your hero, Mario Andretti. Of course, the difference now is that you're older, going 20 mph faster on a Sea-Doo, and there are no angry old men in bifocals standing behind walls of tires and screaming 'slow down.'

Now, it's just you, the water and the Kart 'experience.' In the end, it doesn't get any more real than that.