A few months ago, I replaced Issuma's navigation computer ( http://www.sailblogs.com/member/rhudson/349170
) with a Raspberry Pi 3. The Raspberry Pi 3 has worked well, and performs better than the older Utilite computer that I have used since 2014.
I still have the old Utilite computer as a backup, and I also have an older Raspberry Pi 2b as a backup.
It was much easier to compile and install OpenCPN software on the Raspberry Pi, than it was on the Utilite. I mostly followed the helpful DIY instructions at http://www.agurney.com/raspberry-pi/pi-chart
Learning how to disable the screensaver was the most time-consuming part of moving to the Raspberry Pi 3. It is good to see that this process is now documented simply at https://www.raspberrypi.org/documentation/configuration/screensaver.md