What is the best instrument to control a autonumous boat


I’m a beginner in control unmanned vehicles.

I want know what is the best GPS to control an autonomous boat to sampler water in a dam, the NAVIO2 or REACH?

Hi and welcome!

Navio2 and Reach are different types of devices.

Navio2+RPi is an autopilot hardware platform that is able to run autopilot software stack (Ardupilot) and control drones.
Reach is an RTK GNSS receiver, it is able to provide precise GNSS coordinates in real-time and also log raw GNSS data for post-processing.

So for an autonomous boat Navio2 is definitely a choice.

Thank you for the answer mikhailavkhimenia.

What is the method to calculate the orientation of the vehicle, it is uses a compass or only a a GPS coordinates?

Ardupilot is able to use both compass and GPS.

Sorry for the ambiguous ask.
I’m trying to ask if the NAVIO2 have a built in compass?

Yes, Navio2 has two on-board compasses.