We most likely will get a uses 15'x48" doughboy/lomart pool this week end. It needs a new liner. I would love to make it deeper as I like aqua aerobics and every inch counts. It there a possibility of digging down 6" and having a deeper liner. I have seen variable depth liners but those have a slant and it would be nice to have a flat bottom. There is a good chance this pool is oddly a 15' which might limit my liner choices.