KEY POINTS:
El Dorado or King Solomon's Mines, it ain't. Think more of a treasure hunt by Enid Blyton's Famous Five.
But there is a significant difference. Blyton never foresaw the advent of handheld Global Positioning System (GPS) devices which have helped geo-caching to become a modern day treasure hunt.
Nor did she envisage the websites which have sprung up to co-ordinate hunts, where devotees battle terrain, weather and coded clues to find "treasure" - usually a small cache which contains a trinket, a log book and a pencil, so geo-cachers can prove that they have found the cache, usually craftily hidden.
If this all sounds a bit like the treasure hunt you set your kids in the back garden at a birthday party, think again. Think international. In fact, think global, and know that New Zealanders are becoming adept at this new 'sport' which gets people healthily engaged in the great outdoors and experiencing scenery not found in anyone's back yard.
Thousands of people round the world - and hundreds in this country - are discovering the joy of decoding cryptic messages and scampering across the countryside in search of hidden treasure in almost half a million hidden caches worldwide.
Linda Wallace, 48, of Hamilton happily admits to being a bit of a geo-caching addict. The first cache she found was under a tree, covered up with leaf litter on Wellington's Mt Victoria in November 2005. Wallace says the hardest part was getting down the 45-degree slope covered with tree roots and slippery pine needles.
She rapidly developed a penchant for the activity and, over the following two years, her personal tally of caches found soared to 1241.
For geo-cachers, the value in the "treasure" they find is not what's inside the cache - they usually include only worthless trinkets - but in the numbers they can track down.
"Once you start logging them, you get numbers and it's good to see those numbers climb," she says.
On a productive weekend Wallace, aka Butterfly-lady, can discover up to 20 new caches. She chalked up 137 caches on a recent 19-day geo-caching trip to Australia with a hectic itinerary that encompassed Queensland, South Australia and the Northern Territory.
Wallace geo-caches primarily with her husband Alan Wallace, aka RadioNut50.
"We see ourselves as a team," she says. Alan, who is into technology, is charged with setting up his wife's handheld GPS receiver with the relevant coordinates (sourced from www.geocaching.com) and maps before they go out hunting.
It's not an expensive sport either - unless, of course, you travel overseas to pursue it. The GPS handhelds range from about $100 to $2000 but the most popular are down the bottom end of the scale, meaning cost is not a huge factor. The GPS unit receives satellite information from which it can calculate its location and, according to Linda, is highly accurate. Depending on your GPS, it can take you right up to the last metre, she says.
Wallace appreciates the opportunity to explore little-known locations and says she has found caches from Ninety Mile Beach to Bluff.
"You're going to places where local people have placed caches, they know about the areas and you get to see a lot of areas that you wouldn't normally know were there: parks and historic places and artwork - all sorts of things not on your average tourist route."
Rodney-based Cameron Kerr, 35, a geo-cacher since January 2007 with 696 finds under his belt, also enjoys the connection to the great outdoors.
"People at work think it's a bit freaky at first," he says. "But when you explain that you see nice places, places that you didn't even know were in your backyard ... it's nature-orientated."
Caches can be hidden almost anywhere that has public access - in the city, the country or even the bush. Some extreme caches are placed in remote spots recommended for experienced trampers only while others are hidden under water, accessible only to scuba-divers; some are even hidden up trees, for example.
Each cache contains a logbook into which visiting geo-cachers note their presence. It may be a sophisticated treasure hunt for adults but the bounty in the caches is seldom especially lucrative. Small plastic toys or items with unique identifiers for tracking comprise a cache's typical loot.
The website specifies that caches must not contain explosives, fireworks, ammunition, knives, drugs, alcohol or food. For security reasons, caches must not be placed near airports or military installations where they could be viewed suspiciously. There are stories of caches in the United States being blown up by bomb squads.
Every published cache has a page on the website that records its longitude, latitude, size, degree of difficulty and type of terrain. It also lists the geo-cachers who have found it and notes their comments. Hints about the exact location of the cache may also be included on this page.
A simple code in which letters of the alphabet are rotated 13 positions disguises messages that once decoded say things like: "Nestled between two rocks and eight metres into the grove of oriental tall grass."
The code is not merely to add a layer of secrecy; it's to prevent the purists who'd prefer to find a cache without any assistance inadvertently reading the clue. The diehards, the ones that really want a challenge, won't decrypt them, says Wallace.
Geo-caching began in 2000 when GPS technology meant that precise locations could readily be pinpointed, thanks to the activation of 24 new satellites.
The first geo-cache site was in Beavercreek, Oregon. There are currently 3576 caches in New Zealand - 1623 in the North Island, 1944 in the South Island.
Like all societies, there are etiquettes that must be observed. A key principle is if you remove something from a cache, you must replace it with something of equal value. A spot of elitism is offered for those who desire it; information on some caches is available only to website members.
With thanks to JK Rowling, geo-cachers call people who don't geo-cache "muggles". And cache-site raiders, that is "muggles" who spoil the fun by deliberately ruining caches, are the scourge of this online universe.
The hiding of caches is a critical part of the process. Wallace has hidden 48, mainly around Waikato, while Kerr, who goes by the name TheWonderStuff, has hidden 76 - including one in Anaheim, California, just outside Disneyland. It was his reciprocal way of thanking the local geo-cache community for the fun he had finding some caches in the area recently.
A member known as MissAmerica1 is responsible for managing the physical cache in his absence. If you place them more than 100km from your home town, you need to appoint a caretaker to look after it, to ensure it doesn't go missing, he says.
Kerr is drawn to the sheer inventiveness involved in locating a suitable site and setting up a new cache.
"I just like hiding them. You've got to camouflage the container," he says, adding that while ammunition cans are popular, containers can range in size from a film canister up to a 60-litre container. New caches must be approved by an official reviewer to ensure they abide by the guidelines before being published on the site.
KIWIS BREAK RECORD IN ADELAIDE
A couple of weeks ago, eight New Zealanders travelled to Adelaide, Australia, and broke the Southern Hemisphere record for most geo-caches found in a 24-hour period.
From midnight until midnight on Wednesday 12th December, they found 196 caches - solidly beating the previous record of 128, set in February 2007.
The octet were keen to keep their plans low profile, lest the Australians tried to sabotage their effort.
"We didn't want the locals to go and make them [the caches] harder or hide them or remove them or something," says Gary Fawcett, 40, one of the team members.
"I think some people were being a bit paranoid; I don't think that would have happened but it was secret."
Every detail of the covert record attempt had been meticulously planned since March. The team even had labels pre-printed with their details so they could just stick them into the logbooks, thus not wasting precious seconds on signing in individually by hand.
And it helped having eight experienced geo-cachers simultaneously hunting for the cleverly camouflaged containers.
Every last time-saving detail had been considered: caches located near roads were favoured, any accompanying puzzles had been solved before arrival and the route was plotted to cover the maximum number of caches with the least driving. Even so, the white Toyota mini-van they hired travelled around 600km in a single day.
Fuelled with filled rolls, chocolate, energy drinks and chilled water in day-time temperatures that reached 35 degrees, the eight were oblivious to the picturesque South Australian scenery as they focused on speed and efficiency.
"Most geo-caching is about taking in the environment, the views and stuff but it wasn't really like that," says Fawcett. "Our initial goal was only to get over 130 but what happened is we were going so fast that we kind of kept going."
The team included Fawcett, Nick Hammond, Michael Hawkins and Matthew Crozier (from Auckland), Gavin Treadgold and Gary Turner (Christchurch), Richard Moore (Waikato) and Wayne Champion (Greymouth). Perth-based Ian Mackereth was the driver.
