Geocaching is fun at a lot of levels. For some people, it’s a great way to spend a day in the outdoors with the kids on a high-tech treasure hunt.

For others, it’s more of a competitive activity where they use their handheld GPS electronic navigation units to attempt to log more finds than anyone else on the block, state, country or even the world.

And now Thales Navigation, the company that makes the popular Magellan GPS units, offers a chance to go geocaching for fun and profit in the second annual Magellan GPS Geocaching Contest.

It’s not hard to take part. You’ll need a GPS unit (many different models are now available starting at less than $100), a moderately agile brain and a love of adventure. You’ll also need a computer to log onto the Magellan Web site at www.magellangps.com

Once on the site, log onto the geocaching contest page, fill out a questionnaire, then click on “View all cases” to see some clues that will help you narrow down where the hidden treasure might be located.

Magellan clearly would like everyone to buy one of its units, but any GPS that can read degrees, minutes and seconds out to three decimal places will do the job. And geocaching is a wonderful way to learn how to use a GPS, because it requires learning how to read the unit in conjunction with a map, enter waypoints from given coordinates and even establish backtrack routes that get you out of the bush after you get into it.

“Cache” is a French word for a place used to hide or store provisions in the woods. Voyageurs and other early explorers of the North American wilderness used to establish caches at various locations along their trade and fur routes.

Geocachers hide caches in the woods and fields, but they also stash them in suburbs and cities and even inside buildings. At the moment, there are about 100,000 geocaches in 160 countries, mostly things like old ammunition boxes and Tupperware containers filled with trinkets and logbooks signed by the people who find them.

Magellan has scattered caches in or near major cities around the country.

The point of the game is to help Magellan sell more products, but that’s OK, too. Because if you like outdoor activities, and you don’t have a GPS yet, you should have.

Learn more geocaching at www.geocaching.com.