U-SKI Waterski Trainer Kids have fun and ski with confidence from the get-go with AIRHEAD’s U-SKI U-shaped Trainer. They take to it like a duck to water! It’s really easy for kids to get up on and very sturdy, even at idle speeds. It’s like a cross between a sled and trainer skis, made of durable bamboo. Kids love the fun graphics, the easy to grip handle and most importantly, the gentle ride.