The compass shows the direction from the location you entered to the cache. There's a check mark if you've already found the cache. Icons show what kind of cache it is, as well as any trackables currently reported in the cache. If you click the Google Maps link here, you'll get a map of north Seattle, the original home of Geocaching. But when you click on those words on your cache list, you will see all the caches on the list overlaid on a Google map of your area. When you're looking at the map, you can click on a cache icon to learn a few details about it.
Look for a cache with low difficulty and terrain ratings; 1 or 1. At the same time, look at the cache size. Caches come in size micro, small, medium, large, or unidentified. Unidentified can mean it is a any size from nano to large, or the cache may be small but the container camo may be large, or for some reason the Cache Owner CO doesn't want you to know the size; unidentified regular caches tend to be tricky. Micro-sized caches can be tricky to find, too, especially if they're actually "nano" size; you might want to start with a small or medium cache.
When you're looking at the detail, you can click on the Name of the cache to bring up a page of details.
There you'll get all the clues the CO provided, plus a list of all the logs already recorded for that cache. Make sure the most recent logs are not frowning faces or Did Not Find DNF , or you may be looking for a missing or extremely hard-to-find cache. If you find yourself struggling in your search, click on the link to read ALL the logs for hints. Even though each geocacher may think they haven't given anything away, the combination of comments often gives extra hints beyond what the CO originally posted.
In that detailed description, you will find the latitude and longitude of the location of the cache. You'll need to enter these into your GPS, or paste them into Google Maps to find the location of the cache. Google Maps is a great way to get started and to find caches located in the city, near the edges of parks, and other locations that are open to the sky.
But you won't be able to find a cache in the woods without a GPS device. Don't give up if you don't have a handheld GPS; many portable automobile GPS devices have a way to enter coordinates, and a battery so you can take the GPS with you into the woods. When you get to Ground Zero GZ , the coordinates of the cache location, you'll need to use the hints found in the name and description of the cache to locate the actual cache container.
For another perspective, check out the video from Geocaching. Selecting and Finding Your First Geocache!
Sometimes caches are hard to find; sometimes they are missing. The first thing to do when you can't find a cache is to go back and check the cache description page. Have the last 5 loggers found the cache? Was the last one recent? If not, the cache may or may not be missing. If the cache was last found, reread the description. What hints are in the description? Be aware that GPS devices tend to be a bit skittish in the woods, under power lines, or in between tall city buildings.
The best thing to do is find a vaguely clear spot and put the device down for a few minutes - literally. Then check your location again. Once your GPS settles down, we find we weren't where we thought we were, and it's much easier to find the cache when we go where we thought we were before Sometimes the GPS doesn't want to settle down and give a solid reading. In these cases, a good old-fashioned compass and triangulation are your best tools.
Walk away from the place you suspect, and get about feet away.
Then take a reading on your GPS, and use your compass to locate the line that goes in the direction specified. You'll need to make a note of where that line goes; we often do this by having our caching partner stand in a line with several obvious trees or landmarks. Walk around a ways, and take a second reading, and see where those two lines cross. That's the most likely place for the cache to be located. In this age of Google and Google Maps , we sometimes opt for a Google Maps sighting rather than compass triangulation. Go back to your computer and type the latitude and longitude of the cache into Google Maps.
Then zoom in as far as you can, to get an idea where the cache is located from the map. This sometimes tells us that, in spite of triangulation, the readings our GPS is getting here under the wooded canopy are just too erratic and the cache is really Those things lift up! Yes, the "skirt" around the base of the light pole lifts up. Magnetic Key Holders MKH or film canisters or camo'ed prescription bottles hide well in these tight quarters.
Looking for a Nano? These are tiny, usually black, metal cylinders about the size of the tip of a child's pinkie.
Visit Cacheboxstore to see some very unusual cache containers. Retrieved 21 May The website also supports the discovery of benchmarks in the USA. The parameter n is fixed typically 8 and represents a time—space tradeoff. The Linux Kernel Archives. However, as cache reviewers typically cannot see exactly where and how every particular cache is hidden, problematic hides can slip through.
The log is screwed tightly inside, occasionally requiring a "removal tool. Geo-piles are a popular way to hide a cache, whether they're piles of sticks or stones. Caches are also likely to be hidden inside tree stumps or other tree hollows. And "regular" sized caches aren't always ammo cans - sometimes they're peanut butter or mayo or fluff jars, or various sizes of Tupperware or Lock-n-Lock containers.
Often these containers are well-camouflaged. We've found peanut butter jars coated in decoupage to look like thick sticks, and Lock-n-Lock containers covered in camo-patterned duct tape or spray-painted to match the ground or tree or bush they're hidden in. One of our favorites is in a container with a rubber sheet glued to the top, and then mulch or other natural material glued to that Go home, and come back another day.
You might gain new insight by being away, or you might take that break to contact the Cache Owner CO for a clue. Either way, a little sleep and fresh eyes or fresh clues sometimes makes finding the cache a whole lot easier. With cache in hand, be sure to sign the log sheet or log book in the cache, and rehide it as well as you found it, or better if it seems to be out of place. Then when you get back to your computer, visit the Geocaching.
Then look around the site, and pick another cache to find! Here are a few things I wish I knew when I was searching for those first few caches. First, the "skirt" at the bottom of the light post in the parking lot lifts up, and this is a common location for a cache. This hint will save you the hours we spent over several days looking for our first "micro" cache at a Burger King Second, look for "just another pile of sticks.
Third, know that caches may be hidden inside things, and drawn out with an attached fishing line. Inside the knots in a tree or inside a metal fence post is a great place to hide a cache. Visit Cacheboxstore to see some very unusual cache containers. Premium Members get instant notification when a new geocache is published in their, but sometimes even free members can get lucky and be the FTF.
And the FTF gets recognition on the cache's page, and often receives a small token. We received a ready-to-place bison tube with log for our FTF; we've seen other FTF prizes that include an unregistered geocoin or travel bug, a gold dollar, or a gift card to a local fast food restaurant.
You never know what you'll get as the FTF! You can place your own geocache! Read how to hide a geocache and the Cache Listing Requirements and Guidelines before you select your cache location.
Be sure to use Google Maps to double check your GPS readings for your new cache, and then report a new cache. Your cache will be reviewed and published if approved within 2 days, and folks will race to see who will be the FTF! Now that you're caching, the next thing you might like to do is put some trackables into circulation. What is a trackable? Geocoins tend to travel by themselves, while Travel Bugs tend to attach themselves to an object, known as a hitchhiker We've seen Travel Bugs on a wine bottle cork from Germany, a plush Zebra bookmark from England, and a turtle keychain from Washington state.
And our daughter attached a Travel Bug to a Koosh Turtle that she tracks as it travels around the world. We started a pair of Travel Bugs in Seattle to race home to Philadelphia; one got lost in Montana but one made it all the way home in just over 2 years, and has since been to Denver and back!
Some of our favorite trackables so far are our geocoins, which have found their way all over the world, including Hawaii, two Canadian provinces and nearly a dozen European countries. Tracking them is an exercise in geography and fun! For a list of online stores that sell geocoins, including some very inexpensive coins and travel bugs, visit Geocaching. First, make a photocopy of your coins and bugs, back and front, before you send them out into the world.
That way, should they get lost, you can make another copy, laminate it, and put out a "replacement" of the original traveler. Sometimes you'll be at an event, and discover dozens of travel bugs and geocoins in collections. To log each traveler individually would take forever. There's a better way! LogThemAll allows you to type in or cut-and-paste the codes from multiple geocoins and travel bugs, and log them as "discovered" all at once. It's great fun to get together at geocaching events in your area.
Nationally in the U. There are plenty of smaller local events, nearly always family gatherings at restaurants or parks. Come join your fellow geocachers Also at events you'll often find drawings and geocaching coins and supplies for sale, ideas for creating your own camouflaged caches, and lots more fun. To find Geocaching Events, click on "Hide and Seek a Geocaching," and then scroll down to the bottom of the page for seeking geocachers and click on "Advanced Search. Check them out - many are worth driving quite a distance to attend.
Just this summer, we've been to a couple picnics and zip-lining with geocaching families! Everyone has an opinion on GPS devices, but the reviews tell the tale. Features you might be interested in for your GPS include While this type of unit sounds ideal, with the names and locations of all the geocaches in the U. A tree data structure that recursively uses bitmaps to track which words are nonzero can accelerate this. Similar loops can be used to implement all the related operations. On modern architectures this loop is inefficient due to a large number of conditional branches. A lookup table can eliminate most of these:.
The parameter n is fixed typically 8 and represents a time—space tradeoff. The loop may also be fully unrolled. Count Trailing Zeros ctz counts the number of zero bits succeeding the least significant one bit. For example, the ctz of 0xF00 is 8, and the ctz of 0x is An algorithm for bit ctz by Leiserson, Prokop, and Randall uses de Bruijn sequences to construct a minimal perfect hash function that eliminates all branches: There are then only 32 possible words, which the unsigned multiplication and shift hash to the correct position in the table.
A binary search implementation which takes a logarithmic number of operations and branches, as in these bit versions: Count Leading Zeros clz counts the number of zero bits preceding the most significant one bit.
For example, the clz of 0xF00 is 20, and the clz of 0x is Just as count leading zeros is useful for software floating point implementations, conversely, on platforms that provide hardware conversion of integers to floating point, the exponent field can be extracted and subtracted from a constant to compute the count of leading zeros. Corrections are needed to account for rounding errors.
It is stated here instead of repeating in each code example. The non-optimized approach examines one bit at a time until a non-zero bit is found, as shown in this C language example, and slowest with an input value of 1 because of the many loops it has to perform to find it. An evolution of the previous looping approach examines four bits at a time then using a lookup table for the final four bits, which is shown here. A faster looping approach would examine eight bits at a time and increasing to a entry lookup table. Faster than the looping method is a binary search implementation which takes a logarithmic number of operations and branches, as in these bit versions: The binary search algorithm can be assisted by a table as well, replacing the bottom two "if" statements with a 16 entry lookup table using the final nibble 4-bits as an index, which is shown here.
An alternate approach replaces the bottom three "if" statements with a entry lookup table using the final byte 8-bits as an index. In both of these methods, the initial check for zero is removed because the final table operation takes care of it. The fastest practical approach to simulate clz uses a precomputed 64KB lookup table, as shown in this C language example. Other than a dedicated assembly instruction that performs the CLZ type operation, the fastest method to compute CLZ is reading a pre-computed value from a lookup table.
The following are C language examples of CLZ for an 8-bit, bit, bit input value. The tables must be pre-computed by functions not shown here.
An alternate 8-bit approach could pack two results in each table entry thus needing a entry table instead of entry table, because the bit count is 0 to 8 which fits in a 4-bit nibble. This can in turn be used to implement Newton-Raphson division , perform integer to floating point conversion in software, and other applications. Count leading zeros and count trailing zeros can be used together to implement Gosper's loop-detection algorithm , [52] which can find the period of a function of finite range using limited resources.
The binary GCD algorithm spends many cycles removing trailing zeros; this can be replaced by a count trailing zeros ctz followed by a shift. A similar loop appears in computations of the hailstone sequence. A bit array can be used to implement a priority queue. In this context, find first set ffs is useful in implementing the "pop" or "pull highest priority element" operation efficiently.
FTF: First to Find is a geocaching-themed card game that lets players experience the same kind of emotions that they would get from playing in the open air. These are items you can use as first to find prizes in your new geocaches.
The count trailing zeros operation gives a simple optimal solution to the Tower of Hanoi problem: It can also generate a Gray code by taking an arbitrary word and flipping bit ctz k at step k. From Wikipedia, the free encyclopedia. These four operations also have negated versions: