GPS Is the Key to ‘Caching’ in on Malibu’s Hidden Treasures

• New NPS Program Uses Satellite Navigation to Educate and Entertain Visitors

BY SUZANNE GULDIMANN

It’s called geocaching. Ever since global positioning system technology became available to the public in 2000, this high-tech scavenger hunt game, which uses a combination of Internet, GPS and hiking skills, has been growing in popularity at an exponential rate.
The game of geocaching is said to have been invented just three days after the U.S. Department of Defense announced that it would no longer scramble the satellite navigation system information that makes GPS possible. Today, there are millions of geocachers worldwide. There are an estimated 70,000 caches in California. An Internet search turns up nearly 4000 sites just in the vicinity of Malibu, most of them in the Santa Monica Mountains National Recreation Area.
Geocaching enthusiasts say the game teaches valuable navigation and map reading skills—the activity is a popular activity for families with children—but most just enjoy the thrill of the hunt, and it can be a real thrill. Most geocaches are readily accessible, but some are hidden in locations that may require advanced hiking or climbing skills. Websites provide geocachers with forums to learn about new caches and share their experiences.
Lately, the National Park Service has joined in the game, offering free public GPS workshops and its own set of geocaches.
NPS ranger Mike Theune is working to develop a series of what are called earthcaches in the local parks. Most caches consist of a small waterproof container that holds a logbook for finders to sign. Many also contain trinkets as a reward—geocachers, operating on the honor system, take an item and leave another in its place. There are also virtual caches, consisting of something interesting that might otherwise have escaped notice, like a survey marker, benchmark, or even a view.
Earthcaches offer information on what Theune, whose training is in geology, describes as interesting and unique geologic features rather than trinkets. The logbook exists online rather than in situ, and participants can take an interactive online quiz and see how much they learned about each site.
There are now four official earthcaches in the Santa Monica Mountains National Recreation Area, and Theune told the Malibu Surfside News that he hopes to expand the program to include cultural and ecological sites, in addition to more geology related caches.
Theune’s NPS caches don’t require any off-trail exploration to find, but it helps to be observant. Keen eyes, are in fact, one major benefit of the geocaching phenomenon, according to Theune. Geocachers often report maintenance issues and suspicious activity like abandoned vehicles or vandalism.
The coordinates for the newest earthcache, which made its public debut during a walk led by Theune on Aug. 29, reveal the location of an ancient undersea landslide that is now high in the mountains near Castro Crest. The cache’s name “A Turbulent Time in History” offers a clue to what visitors ought to be looking for. Additional information on the earthcaches, including en-crypted clues that have to be decoded using a cipher, can be found on the Internet.
But it’s not all fun and games, according to Theune. The NPS is kept busy removing illegal cache sites from federal lands. The SMMNRA is a checkerboard of federal, state and private lands, which further complicates the issue. “What is legal in some areas is not legal in others,” Theune told the participants in the GPS talk during the walk to the first of two geocaches—a physical cache located on state parklands, where caches are permitted.
“The problem with physical caches is that they can cause damage to cultural or natural resources,” Theune explained, as the walk’s novice GPS users inadvertently blundered through manzanita and yucca plants in pursuit of their goal. He recounted an unfortunate incident involving a geocacher who buried a cache under a clump of endangered plants. The plants died.
Unauthorized caches in the local mountains have apparently also led to complications involving poison oak, rattlesnakes and falls. “You wouldn’t believe how many people can’t recognize poison oak,” Theune said.
While thousands of geocaching enthusiasts are presumably prowling the hills in search of hidden treasure, many would-be GPS users find the units bewilderingly complex. At another recent hike, one participant was treated to a scenic tour of the entire perimeter of a Malibu area park before her GPS unit triumphantly announced, “You have arrived,” miles from the park entrance she was trying to reach.
“GPS knows where you are by satellite triangulation,” Theune explained. “It keeps track of minutes of longitude and degrees of latitude.” He added that in some ways the device is more like a clock than a computer.
“It’s a sort of space-age descendant of the marine clock designed by John Harrison in 1730 to keep track of longitude,” one of the walkers volunteered.
Longitude, measured in hours, minutes and seconds, is an angular measurement ranging from 0° at the Prime Meridian to +180° eastward and -180° westward. Latitude provides the location north or south of the equator. Together, they can be used to pinpoint an exact location anywhere on earth.
However, in order to use latitude and longitude to calculate its location, a GPS unit has to receive signals from at least three satellites. The process is called trilateration. It only works while the unit is in motion—Theune recommends circling around—and it cannot determine direction.
“That’s the first downfall of GPS,” Theune said. “It’s handy. It tells you where you are, but not what direction you’re going. They don’t have an integrated compass, although the technology is improving all the time.”
The second problem with GPS, Theune explained, is that it points to the most direct route to the entered coordinates, not necessarily the best or safest. Good judgment is required, whether the GPS unit is being used in a vehicle or out on a trail.
Theune stresses that a GPS unit is only a tool and not always a completely reliable one, since it depends on satellite reception that is not always available and a computer and battery system that can experience glitches.
Operator error can also be a serious problem. Theune reminded the walk participants that co-ordinates to destinations are only useful when they are entered accurately. All the GPS horror stories about people misdirected hundreds of miles, or driving off the road or off a cliff, that have become the stuff of urban legend, unfortunately have some basis in fact.
“When we’re on a rescue, the GPS is great,” Theune told The News. “It lets us send accurate coordinates if, for instance, we need a helicopter in to airlift a victim, but we still need to hike in and back out, and when you’re in the back country, it helps to have a map. I always carry a compass and a map.”
Information on the NPS’s SMMNRA earthcache program is available at www. samo.nps.gov. The next GPS walk is scheduled for 9 a.m. on Sunday, Sept. 20, at Paramount Ranch.