There's more to it then just loading some gps cords into your unit. That will get you close to the piles but your still gonna have to find them once you get close. Use only the Martins map as it will give you the exact cords that you need. It doesn't matter which GPS unit you have as long as you know how to use it. Every good map will tell you which Map Datum they use when making their maps(this is the most important element when mapping so your #'s are accurate). You have to read the small print on the map to find out which Datum the Map Maker Used. To know what Map Datum is, google it that will give you some insight. Most Gps units come out of the box in "Default Mode" on the Datum. Go to your unit and find the "Datum settings" and see what yours is set on(it will show a lot of different ones), the one your looking for to use with Martins Map is the "1927 North American Means" set it and start plugging in the cords on that map and you will be right on top of those piles when you get to the lake. If your as old as me a good magnifying glass will help, the writing on his map is rather small.