I have the new HB helix DI with gps on it, however I do not have a map card for it yet, having trouble finding the MICRO SD card in south or southeast states in both navionics and Lakemaster.....My question is can I still mark stumps and brush tops with my unit without a map card in it? I have about 25 trees ready to sink and want to make sure that I can mark them....anymore know if I can still mark gps waypoints withouth the map card ?