I have not found any documentation on this topic as yet. I have a Garmin 8612 XSV and would like to add a 7" or 10" monitor in front of my shifters to view a second screen from my Garmin like the backup camera, Engine data etc. While the Garmin 743 and 943 are pretty, they are so pricey. I see where they recommend even pricier second monitors on their website, no thank you they allude to other monitors being compatible. The Active captain is nice, but only gives me the same screen I am showing on my Garmin screen, so an Apple ipad or windows tablet will not do the job, I believe?

My Garmin does NOT have the "USB DRD" indication but not sure that precludes this from working. This is my back plane that has a USB-C and HDMI Output that I would use for another touch screen monitor https://www8.garmin.com/manuals/webhelp/gpsmap8400-8600/EN-US/GUID-DB5F432F-0A17-4E6A-87FF-9C28203E88E3.html

They also give specs When selecting a 3rd party monitor, verify that the display resolution mentioned above and that the specs of the monitor mention it supports USB for touchscreen control. Some monitors may have screen resolutions and interfaces that are not supported by the 84xx, 86xx and 87xx series devices. https://support.garmin.com/en-US/?faq=m7t8ecpaN01mkR2sDLIcvA&productID=799264&searchQuery=3rd%20part%20touch%20screen&tab=topics

Some screens I have looked at are:
https://www.beetronics.com/10-inch-touchscreen-full-hd
https://www.sihovision.com/full-ip65-high-brightness-touch-monitor/waterproof-monitor-sl100w.html I know Chinese sold and made.

Any help guidance or just random thoughts on the matter would be appreciated. Or am I just being cheap and should I buy the Garmin 743 ($1,099.00) or 943 $1,399.00)

Hope everyone is getting ready for Spring, it is here in Atlanta GA by the way I made a YouTube video on my NEMA network and FOX Marine Engine project I will post a link soon.