I had been a "gotta have paper charts" kinda guy since we started boating... a hold-over from my pilot days (always have VFR charts even when flying IFR). Well, flight crews are using iPads in the cockpit... without the benefit of paper backups. We have been using electronic charts for 6+ years, and still carrying paper backup. If I already have paper for an area, I'm not going to dispose of them, but for any new areas, I feel comfortable with electronic charts. We have the charting on the iPad, both phones (iPhone and Droid), AND a DVD of all US charts that can be put in either of the laptops. All of the above with independent battery sources and can also be plugged into 12v. And, the Raymarine E-80 with charts of the East coast, West coast, Gulf coast, and inland lakes. I think we're covered. :wink:
As far as trusting the electronics, I was taught "trust, but verify." If they are doing what they are supposed to when everything is good, I trust that they will do so when the vis or conditions are bad. I trusted lives to IFR equipment for a lot of years; yes, it was certified and inspected. But, the advantage with a boat is you can pull the throttle back, stop, and re-evaluate the situation... can't do that in the air.
The iPad and phones are not integrated with the radar, depth finder, VHF, and autopilot like the E-80. I consider the iPad and phones to be a back-up, but I would be comfortable using any of them as a primary nav unit (and have on other boats).