Where is GPS antenna on a 2017 R29?

[Mastercraft]

Where is GPS antenna on a 2017 R29?
What does it look like?

I am buying an AIS800 Garmin for transmitting AIS. The supplier wants to program the MMSI number and they say they need the above antenna info. I don't know why they need the info.

 

[fishheadbarandgrill]

Probably integrated into your chart plotter. Not as much an issue for boats our size, but on larger vessels, the exact position of the GPS antenna will help to determine if you are in a constant bearing decreasing range scenario (CBDR) when it comes to calculating a collision.

 

[fishheadbarandgrill]

I should add that the AIS800 does use an internal GPS antenna. Sorry about that. It does not pull from the chart plotter. I have the AIS600, which came with an external antenna.