This is a very well written document from Digital Yacht explaining in straightforward terms what Signal-K is, how it fits with existing NMEA standards, and where they see it going in the future. Now about OpenCPN...
So I have an NGW-1 ISO purchased to feed GPS data to my VHFradio. I found I could just tie into the 0183 output on my chart plotter which works great.
I have not been able to make it work on my laptop because I have no serial port.
is there a way to make it work or do I have to buy the NGW-1 USB.
Yes buy a serial to usb converter cable. There are many bands out there and most work but if you read the OpenCPN manual you'll see recommendations for specific manufacturers.