Depends a bit on how you want it to function. I prefer redundancy, and dislike having someone at one station changing the display on the others. E.g. if I'm working on a chart or radar
down below, it shouldn't mess with the helmsman's display and vice versa
. Of course, I'm also paranoid and consider VNC to add an unnecessary link of dubious reliability
Thus I'd prefer separate systems that are able to synchronize data between them, such that if I create routes, add chart notes, etc on one system they are cascaded to the others.
This can get costly if you have to pay for charts
though. Which reminds me, the last boat I was on had three B&G
plotters, as I believe all can use a single
chart card regardless of which of them has it inserted. This, along with data synchronization, would be useful for OpenCPN.