Problems with the nuvi 255W
There are some major problems with using a car GPS system for geocaching. First of all, the unit is not waterproof. If it starts raining, you need to quickly protect the unit. You should bring some type of waterproof covering. If not, you’ll probably have a broken GPS unit by the end of the trip.
Another issue is that car GPS systems don’t have replaceable batteries. If the unit goes dead while you are in the middle of the woods, there’s no way to replace the batteries, and the batteries only last for about four hours. If you are planning on an all-day geocache adventure, your nuvi’s going to die before the adventure is done. You either have to walk back to your vehicle and wait for the unit to recharge. Or, you can try to figure out where you are going without the unit.
The latter is not advisable, especially if you are not on a known trail or if you are not on a trail at all. If you do plan on using your Garmin nuvi 255W for geocaching, consider bringing a backup unit. You can get a cheap hand-held GPS unit that you can take with you for a backup.
In fact, the inexpensive GPS unit may work just as well as the nuvi. Car GPS systems aren’t as accurate as handheld units. They don’t have an internal compass to direct you where you need to go. You also can’t zoom very close into an area to get a better look at it.
If you do still plan on using your nuvi 255W to go geocaching, charge the unit before heading out into the woods, and bring a compass to help you get to your destination.