Anyone use, or know of someone using, some type of GPS system to document the location of valve boxes? On athletic fields we bury valve boxes several inches deep (sometimes with metal plates laying on top of the lid) to allow turf to grow on top of the valve for safety reasons. (We also lose valves at ground grade in other site play fields as grass creeps over them.) I measure (triangulate for accuracy) and then do up a schematic on CAD. But you know how things are when trying to locate a lost valve even if using measurements, metal detector, probe and/or a 521. How accurate is GPS and what would a decent hand-held system cost? I know there are some very large irrigation consulting companies using GPS to aid in plotting and designing but those systems would never fly with my bosses because of their cost.