RE: MapSource or Blue Chart drue..."mapsource" is the software program that runs on your pc, for all of garmin's mapping products
to your question though this is what i do and it works pretty well
get "us topo" cd's AND the "bluechart americas" cd
the topo maps are far more detailed (though still dated) for inshore & nearshore areas. the bluechart maps are better for offshore use, as they detail navaids, bottom soundings, etc
you can load them both together on a chip, and plug the chip into the 188. i run the topo disc first, selecting the coastal mapsets i want, then save in mapsource. then run the bluechart disc, save the offshore mapsets i want, and save again. then, plug in the disc reader while mapsource is still open, select the saved us topo & bluechart mapsets, download & done |