Club 56,
Assuming that your Vision 42 is similar to my Vision 46 electronics, Garmin AIS600 will give you what you need. But, you will need to keep your AIS300 for the VHF. The antenna is dual but will need to be moved from the AIS300 to the AIS600. Garmin AIS600 has all the parts you need and you basically will use all of the parts in the box. I moved the AIS300, replacing it with the AIS600 so all the cables are the correct length. Then, you cable it exactly as instructed. It took less than 1 hour to install the new unit. I installed the AIS300 upside down immediately above the panel/door which is a much better location that the original location.
I also installed a "silent" switch which I purchased from a hardware store for less than $5. I hid the silent switch in the cabinet to the right of the "nav" station in the white 1/4" thick panel. Strange thing with the silent switch is if you turn it to silent when the power is on, you need to cycle the power if turning off the silent mode.
I assumed that the AIS600 would replace the AIS300, but because it doesn't have the VHF, it has to be an add-on.
The instruction said the "flow-through" antenna would not be degraded but I believe I did lose some distance with the VHF. Otherwise, it works perfectly.
Garmin's site does have the manuals for download as with all their products.
If you have any questions, send a PM.
S.
