Our liner is 3 years old and this has developed in the past year. I noticed that it was happening, but it did not appear to be getting any worse. It in only happening on one side of the pool, the south side in this case. As noted in my sig, I have a SWG and Auto Cover. I have not had the installer of the pool come over to the house, but thought that maybe some of the Guru's would have any idea. If I rub the area, it removes the liner color. Additionally, none of this is happening below the water line, only directly above.
What stumps me is the fact that it is happening only on this side of the pool.
Any help and thoughts are appreciated!!