General A-B Point to Point Set Up
The first thing to be done is establish 2 points, an A point and
a B point approximately 5' from the edge of the pool. The points
should be roughly 2/3 of the length of the pool apart. If, for
example, your pool is 40' long your distance between A and B should
be about 26' apart. The points should be on a flat surface.
Your A and B points if extended with an imaginary line from both
ends should not cross the pool at any point. If this line does
cross the pool you will have to adjust your points.

Continue - Marking A-B Points