@johng As a note on this, ArduPilot’s Developer Code of Conduct specifies that:
Accordingly, if you want to use Navigator for a dive propulsion vehicle you’ll need to do so without using ArduPilot software (including ArduSub), and any help from Blue Robotics employees would need to be limited to how Navigator’s sensors and PWM driver could be programmed and used directly (without ArduSub, and likely without reference to the ArduPilot codebase).