It's way cool-- thanks for the tips. I wish I could upload the maps themselves but it looks pretty easy to upload the waypoints.

I've noticed that the Lakes and Hotspots maps for Washington are pretty lame-- they only include a few of the lakes I would want (Moses and Roosevelt) and not Potholes, Chelan, or the rivers. I got Bluechart, which is great for the Columbia and Snake, but it overwrites the upper Columbia portions of the basemap on my GPSMap 76CS with a really bad map-- no islands or usable shorelines. I didn't expect to get depth readings for that area since it's not officially navigable (and I already know the depths anyway) but it would be nice to have shorelines for navigating in the fog.