We have our primary VHF in the navigation station and a second redundant VHF at the helm using it's own antenna. Our AIS is in the navigation station so I put an A-B switch and just switch from the radio to the AIS at different times.
Usually while underway with large traffic around I'll put the navigation station radio offline in favor of the AIS and use the VHF at the helm for communication.
Works well. I think an automatic switcher would be better but I don't want to spend the money.