If the rider is actively balancing then it doesn’t need to immediately nosedive. In reality that’s the usual effect, but keeping a low center of gravity and trying to keep it balanced go a long way toward a smoother slide/roll instead of a faceplant.
The rider leans forward to accelerate the OneWheel, so they are not "actively balancing" - the OneWheel self-balances "against" their lean. Until the motor gives out, that is.
Simply carving , which is how you turn, requires some balancing by the rider. Going fast over anything but ideal terrain also requires active balancing. If you ride one in any capacity beyond a few mph in a parking lot, you’ll feel it in your legs.
