Planning BlueChart g2 on a computer

[clearsea]

I'm still back at BlueChart and trying to decide on my next GPS, so I'm catching up on BlueChart g2 technology. The Garmin website says that BlueChart g2 charts preloaded on a device or data card cannot be viewed on a computer. In the old days, we installed BlueCharts from a CD to a computer, and then uploaded them to the GPS receiver. We could then view the maps in MapSource to plan passages on the computer and upload the waypoints/routes to the GPS receiver. How does one do that with preloaded BlueChart g2?