answer:Hovercrafts will be practical the day someone invents an anti-gavity shield. Imagine what it takes to keep a vehicle off the ground: fans, jet engine exhaust, etc. Now think of the seals that are needed to maintain the positive pressure: bladder seals, flexible skirts, etc. Now look at your car in the driveway. It is hovering about 8 – 10 inches above the ground, supported by 4 rubber rings inflated with air. And it takes no power to stay there! Do not hold your breath. The laws of physics are hard to beat. Widespread use of hovercrafts is a loooong way off. Get busy working on that anti-gavity shield.