To avoid accidents on the water there are situations when rules help guide the actions of the riders. When two kiters are going in the same direction (on the same tack), and one is going faster and wants to overtake the slower rider, then they must keep clear. The overtaking rider must pass the rider outside of their wind windows so not to cause a hazard to either rider. This means passing up to a kite line length away from the other rider. If you cannot pass the other kiter safely then do not do it. Which side you pass depends on the relative angle to the wind and the skill level of the riders involved. If a kiter is going slow and very upwind, you will pass on their downwind side.