So what was the out come and what did you do. I'm going through the same thing but mine is 2" along one side from shallow to deep and I know exactly why mine settled because of crappy drainage and LOTS of standing water, pool was fine and we had HEAVY RAIN AFTER HEAVY RAIN for about 3 months and this is when it settled and hasn't moved since and added drainage very soon after this happen, concrete patio and gutters (no more standing water-proper runoff) I'm thinking of one of two things. Adding to the coping beam, raising that side and what I'd prefer but worried about cold joint or cutting the high side down.