I notice on most of the Pros boats that most of them have the White Big Hockey Puck external GPS Antennas I'm assuming for there Fish Finders. Question- why are they running there units off of external Antennas when there units have internal Antennas Does the externals give better signals than using the internal antenna in unit. I run the internal antenna on my Lowrance HD 12 and it seems to do what I need But am I missing something by not running a external Antenna?

For accurate waypoints based on sonar returns for a console unit, you would want the GPS antenna at the transom where the transducer is.

"Pros" using the Minnkota Ultrex would have a heading sensor that talks to the iPilot via Bluetooth. That is a white puck also.

Additionally a GPS antenna with heading sensor is used to stabilize the chart view when at very slow speeds. Point1 is the Lowrance version, and AS GPS HS is the Humminbird version.

Look up Lowrance Point one antenna on google or YouTube. I have one and really like the heading sensor to be able to position my correctly on waypoints and also it was night and day difference with the return speed no more waiting for the slower internal gps to catch up with you