I've written a small application that enables windows 8 tablets (or notebooks with GNSS sensor) to use OpenCPN. It's quick and dirty, a work of couple of hours only, but seems to work.
It's been tested inside of a fiberglass boat and the GNSS sensor seems to be able to pick up the signal quite well. Hasn't been tested at sea yet.
See the details here: https://bitbucket.org/petrsimon/geol...ntcp/wiki/Home