I bought an Ulterra from a forum member and I'm going to install it this weekend. I did not get a GPS puck with it. Is this something I have to have to use the spotlock and tracking features? If I link it to a hummingbird graph that already has a gps puck do I still need the MK head unit?
It doesn't come with a GPS puck. iPilot is GPS.
It comes with a Heading Sensor that talks to the iPilot via Bluetooth.
The Heading sensor is used for the Jogging feature, it lets the iPilot know where left, right, forward, and rearward are. GPS cannot calculation direction unless it is moving faster than .6 mph.
It also makes the GPS positioning more accurate.
You don't have to have one or use one. I frequently forget to turn the power on to the Heading Sensor.
You can use the iPilot with its Heading sensor as a GPS/Heading source for the Humminbird if the iPilot is the LINK version but you cannot subscribe to the Humminbird's GPS or Heading Sensor to the iPilot.