I want to buy a Hummingbird 997 si and place it at the console. I have a Lowrance LCX 25c at the bow. Is there a way I can "match" the two so that when I mark a spot on either one on the GPS unit it will mark the same spot on the other unit? I know I can do it Lowrance to Lowrance and Humminbird to Humminbird, but don't know if I can do this. Any ideas?