The sail swings behind the mast like a weather-vane the wind blows past, and the yacht is motionless. It's a question of degree. The sail rope is used like an accelerator. Pull it tighter for more speed - let it out to slow down. Experienced land-sailors can hike one wheel in the air, maintaining a precarious balancing act with the yacht on the verge of tipping over.
Injuries are uncommon.
You are more likely to catch a cold from the wind chill than break any bones. The grandly titled yacht has the deceptive air of a glorified kids boxcarts with one wheel missing. The front wheel is steered by the feet while your arms work the sail rope. The two rear wheels on the yacht I am using are from old Honda motorcycles. For streamlining, the pilot lies flat in the glassfibre shell.