Geocaching: Use GPS navigation system for treasure hunting in Maine Geocaching is an entertaining outdoor adventure for GPS navigation system users. Participating in a GPS treasure hunt is a good way to take advantage of the wonderful features and capability of a GPS unit and explore Maine. The basic idea is to set up caches all over the world and share the locations of these caches on the internet. GPS users can then use the location coordinates to find the caches. Once found, a cache container may provide the visitor with a wide variety of rewards. All the visitor is asked to do, if they find something, is that they try to leave something for the cache. A Global Positioning System (GPS) unit is an electronic device that can determine your approximate location (within around 6-20 feet). Coordinates are normally given in Longitude and Latitude. You can use the unit to navigate from your current location to another location. Some units have their own maps, built-in electronic compasses and voice navigation, depending on the complexity of the device. A cache can come in many forms but the first item should always be the logbook. In its simplest form a cache can be just a logbook and nothing else. The logbook contains information from the founder of the cache and notes from the cache's visitors. The logbook can contain much valuable, rewarding, and entertaining information. A logbook might contain information about nearby Maine attractions, coordinates to other unpublished caches, and even jokes written by visitors. If you get some information from a logbook you should give some back. At the very least you can leave the date and time you visited the cache. Larger caches may consist of a waterproof plastic bucket placed tastefully within the local terrain. The geocache container will often contain the logbook and any number of more or less valuable items. These items turn the cache into a true treasure hunt. You never know what the founder or other visitors of the cache may have left there for you to enjoy. Remember: if you take something from the cache, it's only fair to leave something in return. Items could be maps, books, software, hardware, CD's, videos, pictures, money, jewelry, tickets, antiques, tools, games, etc. It is recommended that items in a bucket cache be individually packaged in clear, resealable plastic bags to protect them.