thanks for the reply, makes me feel like i helped someone. now that you have it changed to nad27, get into your setup and change it to UTM, once you do that, take a look at your topo map and you will see a small number and a large number on the sides and top and bottem of the map, if you connect these numbers from top to bottem and side to side you will have utm grids. now take a reading with your gps.it should look something like this: 18 S 0303390 UTM 4279350, work with the last five numbers of each, example: 03390 will get you into the grid for 03 and 79350 will get you into the grid for 79 above and to the right of these numbers if the grid square you will be using, once you find the grid square, use the remaining three numbers for each to find your exact location within the grid. give it a try and let me know how it comes out for you, heck, i might make you an instant map reader.