If you've designed a car that will be used to enjoy the marine environment, the last thing you want to do is start messing up that environment. That's one of the reasons the sQuba is a zero-emission vehicle. While it requires five separate motors, all of them are electric. This submarine doesn't directly release any pollution at all.
There's a practical reason for using electric motors as well. Combustion engines are notoriously difficult to operate underwater. An exhaust pipe or tube long enough to stick out of the water would be necessary, and that would severely limit the sQuba's submarine mobility.
Why five motors? One powers the rear wheels when the sQuba is on land. It puts out 54 kilowatts, about 72 horsepower -- enough for a top speed approaching 75 mph. Another motor drives each of the propellers when the sQuba is in the water, pushing the car to a surface speed of about 3 mph (less than 4 knots). Underwater, it only moves about half that fast [source: CNN]. The last two motors are Seabob jet drives which power the steering jets at the sQuba's front. These jets steer the sQuba by directing jets of water through swiveling louvers.
The green aspect doesn't stop at the power plants, however. The sQuba's lights are LEDs, which use less power than conventional lights. And taking the sQuba underwater won't leave a trail of polluting oil behind. The car uses Motorex-developed lubricants, which biodegrade rapidly in water.
Next, we'll find out how a car goes from road to water to underwater.