I'm glad that this subject came up.
I just bought one of these gismos for $40 odd
www-gps2003-com.membership.editmysite.com/login which is supposed to turn your laptop or computer into a GPS receiver. Ive not tried it out yet and probably wont for a while but if you have a look at the splurb on the website it would appear that it will operate with a whole range of programs:
Garmin Map, AutoRoute, Streets & Trips, Google Map, Google Earth, Map King, TomTom, Navman, Magellan, SeaClear, Marine ChartPlotter, Memory, Waypoint, Explorer,
The intention was to be able to use it with Navionics but if they wont play then I can use one of the above. I already have the Navionics on the Lowrance and on my Ipad Air. Unfortunately the Ipad does not have GPS capability, only works of cell towers, which is why I bought this antenna.
Ill let you know how it goes when I get back to the old girl and get her out on the water.