The pool was put in 25 years ago and so there is certainly no above-ground evidence remaining such as trenches or depressions, etc. I would imagine when the fence company put up my fence after the pool was built, it was easy for them to see where the lines were by the lack of new grass where the trenches were dug. So, I'm at the point now where I need a new fence. I saw a thread here about a divining rod procedure. I've always been skeptical of this but, hey, if it works I'm game. Any other ideas? The fence company obviously does not want to use their post hole machine and wind up going through either a skimmer, return, or optical line. And so that leaves using the hand digger in areas of uncertainty. This really has me worried. I wish there was some way to know for sure where the lines are. I checked my pool blueprint but it only gives a sketch as to plumbing lengths for each line and a rough drawing of where the lines are approximately located relative to the filter - it's not scaled too well. The fence foreman looked at it and deemed it to be of little assistance. Thanks for any suggestions.