We use our ipad all of the time for this. We have a Garmin plotter as well, but sailing up into Canada this summer it lacked cartography. I would recommend it to anyone as a backup, or if you are taking a trip somewhere where you don't yet have charts. The Navionics apps are cheap and the iphone versions will run (and are even cheaper, though lower resolution). iNavX has it's problems and I can't recommend it. I really wish I could get a refund, both for the app and the international charts from Fugawi. The charts are essentially rentals with a time out on the time you can download them, so if you ever need to restore your ipad later you are SOL.