For what it's worth we have been using a Pi2 now for a while for primary navigation
using OpenCPN latterly OpenPlotter 0.8.0
It is fully integrated into the boat we have a Digital Yacht AIT2000 AIS transponder connected via USB and have wind connected via NMEA
to the AIT2000. We drive the DSC radio
from the AIT2000. We drive the Autopilot
and a cockpit
repeater via a Serial to USB converter and OpenCPN.
Apart from no OpenGL it works fine. I look forward to the day we have a native OpenGL driver and OpenCPN versions for the pi.
We also use the pi for games, email
etc. We can also connect via phones and tablets.