This is a common problem. The Major suppliers think we all have deep pockets - "it's no problem, just upgrade"
You can make your own cable, even without the correct
plug, especially if you don't take the unit out of the
boat. I cannot remember if the Connector on this plotter are pins or sockets. Either way, there are only 2 wires required for the AIS connection- pin 3 is (white) +
NMEA in and Pin 1 (Black) or sheild. The AIS
NMEA - is not used. If it's a pin, you can carefully solder the cable on directly. If it's a socket, put a pin on the
cables and
plug them in. Its not fantastic, but it works. The correct plugs seem to be impossible to get...
Good luck!!
Matt