Anne
Have you managed to get AIS data overlayed on your Navionics with the Axiom 12? The Axiom9 will not transmit AIS information on its Wifi signal
If not, the Yakker for £70 is a really simple WiFi gateway add on. I looked into all of the others such as Digital Yacht etc, but i wanted to see if it would work and the Yakker was the cheapest option. 1 hour to install, and when at anchor we can switch all the Nav instruments off, leave the Yakker running and use Navionics / Yakker as an anchor watch, with very low battery drain.
Regards
John