Hi,
Today i managed to load a Bluechart Pacific v9 map onto my Nuvi 1390T. First i loaded it into mapsource. Selected the maps i needed. Exported the maps to device into the Maps folder. Unlocked the image. Selected the map in settings/maps/info and it works. Now i can use it to go fishing. I water proved it in a clear zippy bag and it also floats.
Enjoy