Just noticed there is a spot larger than a softball that is sunk-in about 2 ft from the top of the liner. The liner is only 8 months old. Doesn't seem to be losing any more water than usual. Any ideas what the problem could be, and what needs to be done?
EDIT: The indentation wasn't there in August. It's right below the diving board, almost dead center of the pool. Could there have been a light there at one time, and when the previous owner replaced the liner, they just covered over it?