Consider the Lowrance iFinder H2OC. A "real" marine/outdoor handheld that can use a variety of chart cards (including the Nauticpath one), uses AA batteries, comes with a cigarette lighter power cord, and no annoying touchscreen interface.
May do that, after all, Jim. The Admiral and I have been researching the Garmin Nuvi 500 and, well, let's just say: 1. It ain't all it's cracked-up to be for non-marine use and 2. From what little marine use feedback I've seen, it's not that great.
The two biggest complaints I see are: 1. Display just doesn't cut it in bright sunlight. 2. Battery life is nowhere near
Garmin's eight hour claim.
For the Lowrance H2O C, OTOH, I'm reading pretty consistently good reviews.
You know: There's absolutely no reason whatsoever that Garmin, Lowrance, Magellan, TomTom, or whomever, can't
make a good, portable GPS that would do it all. It's just electronics, software and data. They simply choose not to so so.