I'm interested in hearing from those of you who use a phone or electronic "tablet" to run your charting/navigation tools for multi-hour paddles, and what kind of battery life you are getting. My iPhone 5's screen is pretty small and I can only seem to get about 3 hours of paddling in before it's dead, running Bluechart Mobile. The screen size is better than my Garmin GPS, but I can get a lot more out of the batteries in it. I've turned most everything off in the iPhone that I can think of to extend the battery life but 3 hours seems to be my limit. If you're able to get 6 or so hours of operation running a chart/nav program I'd really like to know the details. iPads? Android based tablet? (never owned or used one) Thanks and cheers.