A cross rack is a job in a sailing contest, with the end point being upwind from the starting point. So it's windy.
In sailing matches, a buoy is flooded. A piece between two buoys is called a shelf. If the wind comes from where dangers should be, it is not possible to go straight to the next buoy. However, by sailing winds, more or less a danger can be taken towards the next buoy. Because the rate is not direct, you must always switch between left and right; This is called one or another. The track that needs to be crossing is called a cross rack.
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