I've used a Magellan Navigator handheld for many many years in some pretty remote areas. It was something like a $100 unit when I purchased it, but it has continued to work well. The downloaded charts haven't done me a lot of good on the water. My practice has generally been to navigate off of a map and to use the GPS to augment.

Make sure you carry extra batteries until you know the life of your unit.

Don't trust your cellphone navigation aids (or tablets either) as far as you can through them. This is especially true in wilderness areas.

A good map and compass should be your primary choice.

Eric M.