[0] Upwind Capabilities [Windsurfing] About 45° from wind direction (strong wind) depending on the skills of the rider. The sail board's center line runs virtually parallel to the track line, as most lateral forces are encountered by the tail fin and little edging is required. Because of this, upwind courses are fairly fast. Fastest speeds are achieved at broad reach. [Kiteboarding] 
About 70° from wind direction. The more a kite board tracks upwind, the more its leeward side must edge into the water to resist lateral drag. Upwind riders adopt a similar stance to kite fliers onshore, who slide their feet forward in the beach sand to brake the kite. The kite board's center line is way off the track line, dramatically reducing speed.