I bought a rural property and I am attempting to find my marker pins using the surveyor map and surveyor coordinates (not actual GPS coordinates; I'm referencing surveyor coordinates such as "S00 35' 03" W" which I don't funny grasp but am learning). Starting from one pin I need to head roughly 51 degrees and walk it for 1600 feet to the next pin. Trouble is, there is no direct path for 1600 feet. In fact, there is a 110' straight drop off into a gulley that is on my property that requires me to walk several hundred feet to get around it. I need an application that will get me back on course from my original heading as well as let me know when I've travelled 1600 feet from the original point without including the steps I took to get around the obstacle that prevented me from walking in a straight line. In addition, the GPS apps I've tried are dependent upon having a data connection and my rural property has no cellular signal. Any help would be appreciated, thanks!