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Walking in circles


Blue Crab Brigade

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So we've been looking for a cache three times and everytime our GPS goes crazy and we are frustrated! We'll walk to where it says to go then it will tell us to go 30 feet in the other direction. Could bad weather effect coordinates? It doesn't do this anywhere else!

 

What kind of GPS do you have? Is the cache area under tree cover or near buildings? Weather shouldn't have much of an impact.

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So we've been looking for a cache three times and everytime our GPS goes crazy and we are frustrated! We'll walk to where it says to go then it will tell us to go 30 feet in the other direction. Could bad weather effect coordinates? It doesn't do this anywhere else!

 

Actually I see you have been caching near me. What cache is this?

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I know, I hate it when this happens...I get dizzy!!! Yes, it happens to all of us. Just turn the darn thing off and look for the most likely hiding place. From the cache page you saw what kind of cache it is, Micro, Small, maybe an ammo can. Use that information and the hint if you choose to, and look for a likely hiding spot. Do you see a pile of leaves or sticks, maybe rocks? Maybe the hint or the cache description told you that it might be hanging in a bush or shrub. Ohhhh, it there your job is to find it, and it's no doubt camo'd to not stick out like a sore thumb. Some are hard and some are easy. This is the fun part of the game. Good Luck and don't give up!!!!

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You may be expecting a bit too much from your handheld GPS unit. In general, these small units have an accuracy around 20 feet. Add that to the unknown error of up to 20-25 feet for the hider and you may have to search an area within 40+ feet of where your GPS says ground zero is. While you will find many caches within 20 feet, it isn't unusual to be further away. When your GPS says you are about 20-30 feet away, put it away and start looking for likely hiding spots.

 

Weather conditions including rain and clouds and fog should not affect the unit very much at all. If you are close to buildings, large paved areas, cliffs or near electrical lines you may be experiencing a multipath error.

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Quite frankly (and by reading here it's unusual), my GPSr (an old Magellan Meridian Color) is pretty accurate most times. It takes me right there very often. But, those times when it shows five feet and the next second thirty feet and the next second eight.... I just put it in my pocket and rely on my "cache sense" to make the find.

 

But, as you get more finds in your area, you'll note patterns. One of our prolific hiders uses his cell phone when placing caches. Nine out of ten on his placements, if I'm 30 feet due east of his published coordinates, I'm probably standing on or under the cache. Another fellow, an avid fisherman, has a good Garmin GPSr and his GZ coordinates are right on the money with my old girl's.

 

So, when heading out, note who is the hider as well as the rest of the information. Just knowing who hid the thing might be hint enough.

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What I usually do is instead of the GPSr "pointing" to the cache for me, I select the screen where I can see my current lat-long coordinates, and then compare that to the coordinates listed for the cache (I carry a small notebook with the basic info for each cache and refer to that).

 

FTR, I've found every cache so far with a cheap 5-year-old Garmin Geko 101.

Edited by VickersDavis
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Once you're in close (within the EPE) your GPS doesn't know exactly were it is in that tiny circle, so you will see

the arrow pointing all over.

 

Also, if you have a unit that does not have an electronic compass, once you slow down it no longer knows your direction of travel. Since most cachers slow down as they approach the cache, the arrow is going to bounce all over the place. To address this, back up 50 or 100 feet and approach the area again at a brisk pace. The arrow will straighten right out.

 

Finally there is signal bounce which will sometimes fool you GPS into thinking it's 50 or 150 feet away. This is most common in ravines and near cliffs and tall buildings, but can happen anywhere.

 

All of this is normal behavior. Once you are within 30 or 40 feet you probably shouldn't even be looking at your GPS anymore. Just put it away and look for the cache. If you come up empty, take it out, walk away and come back ata fast pace....or make a wide circle around the seach area and watch where the arrow points most of the time.

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What I usually do is instead of the GPSr "pointing" to the cache for me, I select the screen where I can see my current lat-long coordinates, and then compare that to the coordinates listed for the cache (I carry a small notebook with the basic info for each cache and refer to that).

 

FTR, I've found every cache so far with a cheap 5-year-old Garmin Geko 101.

Most of the time I use the "Go To" arrow to find the cache, but in some places, like in a canyon with lots of signal bounce, I use the above method to match up the coordinates. Following the "Go To" arrow, that was sometimes pointing to mid-air, was impossible in that situation . . .

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What I usually do is instead of the GPSr "pointing" to the cache for me, I select the screen where I can see my current lat-long coordinates, and then compare that to the coordinates listed for the cache (I carry a small notebook with the basic info for each cache and refer to that).

 

FTR, I've found every cache so far with a cheap 5-year-old Garmin Geko 101.

 

My grandson uses one of those old yellow gekos and he's usually ahead of me in finding the spot on those rare occasions we get to cache together. Nice little unit for the price.

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For the times that I can't seem to find the cache, I'll walk away about a 100 feet and approach from a different direction than I originally did. This may give a different location and more often than not, I'll then find the cache.

 

If you are coordinate-savvy and have an independent compass, you can set your GPS unit on "average" (usually) for marking waypoints. Then stand there for a couple of minutes. It'll give you an average reading for the point you're standing on.

 

If you're using decimal degrees (DD.DDDDD), each 5th decimal place is about 1 yard/meter/pace. If you're doing decimal minutes (DDMM.MMM), each 3rd decimal place is about 2 yards/meters/paces. If you're using DMS that only go to the 10th of the second (DDMMSS.S), you should be using one of the previous two because that's only good to 3 yards/meters/paces.

 

Now, you find your averaged spot. You then figure out how many yards/meters it is to the required location and pace it off using the compass. For example, if your averaged spot is N33.11111 and W117.11111 and you have to get to N33.11121 and W117.11121, that means you go 10 paces North and 10 paces West.

 

However, you must remember that perhaps the cacher's GPS was off, or whatever. So once you get within about 30 feet (10 meters) of the spot you should start lookin'.

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Knowing what unit you are using could be rather helpful.

 

I use a pair of Magellans and consistently have the same issues which leads me to believe it is an issue with Magellan and not the hider or the particular unit.

 

My GPSr will usually send me 30' past GZ and then flip back.

I have also noticed that the units can be particular about the direction I approach from, i.e. if I am coming in from the North and the unit doesn't like it, it will give chaotic readings and refuse to settle down. To remedy this, I approach from a second and third direction and usually the unit will beeline to GZ.

 

Hope this helps!

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What you are describing is what is often referred to as the 'drunken bee dance', for obvious reasons. Consumer GPSr's have a maximum accuracy of about twenty feet (six metres). Once you get within that distance of a geographic point, the GPSr will go crazy, because you have gotten as close as the unit can accurately represent.

 

 

A lot of people will get within twenty feet or so, and then start walking a circle around the apparent target point. The center of the circle will give you an indication to within a couple of feet of where your GPSr has the point.

 

 

Remember that the GPSr of the person who placed the unit may be twenty feet off in one direction, and your may be twenty feet off in another direction. So, you could have as much as a forty-foot discrepency between the placer's ground zero and yours. Many placers will use waypoint averaging when they place a cache to reduce this error..

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There is one cache in the Houston, TX area that has driven me crazy. It is under or near power lines. As long as I am about a hundred feet away I am ok, but as soon as I start to get closer my GPS goes crazy. I have not been back since I upgraded to the 60CX with the sirfIII chip. Maybe I will finally find that dratted thing.

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Check the current 'accuracy' the GPSr is getting. If the accuracy is only going down to 30 feet, then don't be surprised when it jumps 30 feet.

 

My general rule is to set down the GPSr and start looking as soon as the 'distance to WP' is less than the accuracy of the GPSr, no matter how tempted I am to get the distance down to zero :lol:.

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