subject: Why You Need A Compass And A Gps For Serious Adventures [print this page] Many people, mistakenly believe handheld GPS units completely replace the old standby -- a handheld compass (and its map companion). For short hikes on your home turf, perhaps, but for serious outdoor activities, here are three reasons why you should bring your compass and map.
GPS Units Do Not Display Directions Accurately Unless You are Moving
If you are standing on top of a mountain trying to figure out which direction you are facing, you can forget getting an accurate direction from a GPS unit. The navigation arrow will bounce all over the place.
Some handheld GPS units and newer iPhone models have built-in electronic compasses that work independently of GPS satellite communications through a technique called magnetic induction. These electronic compasses detect the Earth's magnetic field, producing the same result you would get with an analog compass. Accuracy of sophisticated electronic compasses for marine navigation can be very high (to match the 4-digit price tags), but don't expect more than 2 to 5 degrees of accuracy with your handheld GPS or mobile device compass.
GPS Display a Limited Amount of Fine-Scale Information Unless You Zoom Out
The overview you get from studying a map, which always displays its finest-scale features, provides great information about distant features that you may be able to recall when you need to. GPS screens either have to be panned or zoomed, or both, to show you the same information. So a good old-fashioned paper (laminated) map is a must for adventurers. Unfortunately GPS units and phones make poor protractors for plotting courses on a paper map. A baseplate compass does the job perfectly.
Analog Has Staying Power, Not Battery Power
Finally, the possibility of a malfunction is much smaller with a handheld compass. Rugged GPS units rarely just stop working, but it does happen -- especially when they get dropped on hard surfaces. They also go through batteries very quickly if you are referring to them constantly. A better solution is to use your GPS power sparingly and refer to your battery-free compass often.
