I am rigging a Garmin GPS system in a new boat and I am wondering about repeater capabilities. Ideally, I would like to have a second screen at my forward helm station that shows the same info as the inside main screen. I am mostly interested in the chart, speed, and depth features. I see the GMI 10 can repeat instruments, but I don't see that it rebroadcasts charts. Currently, it seems I would have to install a second GPS in the forward helm. While that may be cost effective it means I have to enter all waypoints etc twice and also means I would have to have two antennas as I understand it. Any advice on this would be appreciated. Thanks.