I have a Humminbird 1198 and the I-pilot link. I mark a structure that I want to fish. I mark and hit Goto. The Humminbird GPS puck is at the back right of the boat. The transducer is also back right. Which GPS does the I-pilot use, the built in one the I-pilot has which is on front of the boat or the Humminbird puck that's on back?