I use OpenCPN for my computer-based navigation as a redundant system to my Raymarine GPS and chartplotter(s). I have found that OpenCPN (free software) will allow me to download free GRIB files, and that these files interact with a free boat routing software called qtVlm using user-supplied polar coordinates (as can be found in the Amel Yahoo files section). Works well.
Because I wanted to download email and GRIB files when out of WiFi range, I recently purchased a Pactor modem so that I can use the SSB to access both Sailmail and GRIB files. Other than the $250 per year cost of Sailmail, it is now all free. The Pactor modem was expensive, of course, but so is purchasing a sat phone.
