I found a manual for the Garmin puck here
On page 36 (Appendix E) they discuss sensor configuration software
, which can be downloaded. If that software runs on Win 8 (and that's maybe a big if), it may help you see and set the params of your Garmin puck.
Most USB GPS pucks that excrete NMEA0183, like yours, appear to a PC as some form of serial-USB adaptor, and your NMEA0183 stream shows up a virtual serial
COM port... eg COM9.
I've not yet had the pleasure of trying to use Win 8. So I have no idea what tool/app one could use to check serial ports
on Win 8.
PS - Linux
has this sorted out. You could maybe also install Ubuntu or similar on your laptop (dual-boot, so you still have Windoze), and/or you could try booting on a USB stick with Navigatrix
, which is a live "marine" Linux
distro that has OpenCPN and other marine
goodies, and you can boot on it without mussing your hard drive.