External AHRS Integration (VectorNAV 300T)

Hello,

I am trying to integrate a VectorNAV 300T into a blue robotics blueboat.
I have configured the VN300 to send out binary messages according to the ardupilot external AHRS library found here (on line 44): ardupilot/libraries/AP_ExternalAHRS/AP_ExternalAHRS_VectorNav.cpp at master · ArduPilot/ardupilot · GitHub
I have confirmed that the wiring is correct and I can see the data coming out of the serial 2 (TTL) port.

Next, I have followed this ardupilot guide to set the parameters:
https://ardupilot.org/plane/docs/common-external-ahrs.html

After powering up the vehicle, the VN-300 appears to do absolutely nothing. Is there anything else I need to do? Does ardurover even support external AHRS or is this just for planes/copters?

Thank you all for the help.
Cheers

Anyone have any ideas?