I have a Oregon 400c which I have installed a SD micro card with topo maps with your help from this site. I have read the tutorial on changing maps with the Oregon and understand how to do that. The Oregon now shows all these new topo maps which are enabled. Is it my understanding that I disable all these new topo maps to use it as the marine Plotter and when I use the Oregon on the trail I would disable the marine map and enable just the state that I'm hiking in? Also the Trails download, would I also keep that enabled along with the state I'm hiking in. Thanks for your help.
The profiles feature on your Oregon is a simple way to accomplish this with a single menu command. It will remember all the current settings and allow you to activate them. So you would create (or edit the existing) Marine profile that only enables the marine map. Then create a hiking profile that enables the topo and trail maps.
The trails maps are transparent and intended to be activated at the same time as a topo map for your area.
Thanks Boyd I was able to put it all together with your help and the Garmin Oregon owners manual. Setting up the different profiles works pretty slick. Thanks again.