We run 15# Maxima ultra green mono.I have dive charts I reference but we run lines at several leads to find out what's catching that day and change to the depth that's catching on the other lines.Its more important to calibrate all the rods so you can match the depth catching.With current and other factors contributing to the actual depth of your lure,it's not an exact science on how deep your lure actually is.Now if only running 3 lines,it's harder to find the correct depth catching.Many times too the fish you're catching don't coincidence with the fish marking on the sonar.