The Garmin eTrex line has always occupied the lower end of their line of trail GPS receivers, while the Montana line as been at the top. While all Garmin GPS units will do an excellent job of calculating and displaying your location, the various units have different features. The question is, which of these features are necessary for wilderness navigation, and which are merely nice to have?
I’ve been using handheld GPS since the first civilian handheld came on the market, the classic Magellan, and in that time I’ve reached some conclusions. The features I consider essential are:
- State-of-the-art GPS receiver chip and antenna
- Multi-satellite GPS
- Long battery life or user-changeable batteries
- Built-in or uploadable maps
- Color display
- Light weight
- USB interface
- External memory (micro SD card)
And the features that are nice-to-have but not essential:
- Differential GPS
- Magnetic compass
- Barometric altimeter
- Routeable maps
- Bluetooth
- Wi-Fi
Essentials
The first two are important because the better the GPS chip and antenna, and the more satellites it can use, the better the receiver will be at getting fixes in difficult conditions- when the sky is partially obscured by canyon walls or dense forests. The receiver must have a long battery life, both in the case of rechargeable batteries that are not user changeable, or single use batteries that can be changed. You especially don’t want to be caught with a dead rechargeable battery as you find your way back to your vehicle in the last light of the day, for example.
Detailed topographic maps are a must and they must be user-upgradable and updateable. A unit without maps takes you back to the early days of handheld GPS, when you had to manually plot coordinates on a paper map. While I still feel it’s important to carry a paper map if you’re traveling cross-country on faint, little-traveled trails, or otherwise navigating away from well-marked and well-traveled trails, not having to manual plot and enter coordinates eliminates a major source of errors.
Having a color display makes the maps much more readable and useful, and the slight battery life advantage of a monochrome display isn’t worth it any more.
If you’re backpacking, weight matters, but not so much for day hiking, paddling, mountain biking, hunting, or exploring back roads.
The receiver must have a USB interface so that you can update the firmware and transfer waypoints, tracks, and routes between your computer and the unit. It’s much easier the plan and create routes with a computer than on the receiver itself.
And finally, a micro-SD card slot greatly expands the storage capacity of the unit. While the internal memory of all current units is enough to store more waypoints, tracks, and routes than you’ll ever need, maps take up a lot of memory, and the ability to store them on a memory card is essential. You can also have different map sets for different areas or activities on different cards.
Nice to Have
The extra accuracy of differential GPS just isn’t necessary for land or water navigation. Multi-satellite GPS receivers are already more accurate than te most accurate maps.
All GPS receivers have a compass page that shows your heading and your course, but on units lacking a magnetic compass, the compass page only functions when you are moving. The unit calculates your heading and course from successive position fixes as you move. Since you should always carry a magentic compass as a backup, having one in your GPS receiver is not essential.
GPS receivers display GPS altitude to an accurancy of about 200 feet, but a barometric altimeter is abut 10 times more accurate, if you set it to a known altitude or pressure before setting out. Accurate altitude is nice to have, but not essential for most wilderness activities.
Routeable maps let your create a route that automatically follows a trail or a road. This is extremely useful when planning a trip on your computer, but not so much in the field.
BlueTooth and Wi-Fi connectieity allow you to share data with other units, transfer data bettwen a computer and the GPS receiver without a cable, and let your phone send notifications to your GPS unit. Nice, but not essential.
What to Buy
So where does that leave us in Garmin’s current range of products, as the only manufacturer still making handheld trail GPS receivers? With the GPSMAP 65. None of the eTrex line have both a color screen and the ability to receive all of the current navigation satellite systems. The 65 comes in two models, one with and one without a magnetic compass and barometric altimeter. And it has all of the other nice-to-have features except differential GPS, so you really can have your cake and eat it too.
Garmin GPSMAP 65s (with compass and altimeter) on Amazon
