The Global Positioning System receiver that Jennifer and Forrest Wicks used wasn't as precise as they would have liked.

The distance to the treasure they were seeking was way off - the receiver was pointing them in the wrong direction.

They already had found the geocache, however, and they knew to ignore the GPS unit.

"Trees can obstruct a satellite," Mrs. Wicks said. "Weather can obstruct a satellite, and especially electricity."

On this hot August morning, it probably was the trees in Hopelands Gardens causing the problem. The couple was demonstrating how easy - or deceptively easy - geocaching can be.

A popular adventure game, geocaching has a large following in the area, Mrs. Wicks said.

The high-tech treasure hunt works this way:

- After purchasing a GPS receiver - Mrs. Wicks said one is helpful but not necessary - visit www.geocaching.com to find a cache to search for in your area.

- In Aiken's ZIP code, for instance, there are 298 hidden caches. The listings describe what type of cache it is, and the Web site maps out where the closest caches are. The results also can be displayed in Google maps.

- Plug the coordinates for the cache into a GPS receiver to start the search. The receiver can get you within about 30 feet of the prize, Mrs. Wicks said.

"And then you have to use your deductive skills," Mr. Wicks said.

After you find the cache, you can sign the log. If you take one of the little prizes left behind by other adventurers, you should leave something in its place.

The prizes can be as simple as a toy car or extra batteries, or coveted geocoins, which are rare and highly sought after, the couple said.

The cache in Hopelands Gardens, for instance, has a toy car, a pacifier left by the Wickses and other trinkets.

The key to finding the cache, they said, is to realize that it has to be hidden from nongeocachers. "You don't want regular people to know they're there," Mrs. Wicks said.

To add difficulty, the cache sometimes is in a place that could be considered too obvious."You can be standing on it," Mr. Wicks said.

Some of the caches are virtually invisible because they're so small. Caches range in size from extra-large containers to nanos not much larger than a screw.

A teacher at Chukker Creek Elementary School successfully lobbied for geocaching to be included in physical education, Mrs. Wicks said, and the game is spreading in the Aiken County school system.

It's a good way to get outside, see the community and get some exercise, the couple said.

Taking the children along is a good way to get them away from the television, Mrs. Wicks said.

Geocachers can create new caches to find at www.geocaching.com, which also has the most listings for the hidden trinkets, she said.

Reach Sandi Martin at (803) 648-1395, ext. 111, or sandi.martin@augustachronicle.com.