HIPS-meister

I think it's entirely correct to presume that, if you can confirm that the coordinates are 100' off, some error has probably been made. Simply notify the cache-owner privately, providing the coordinates you received especially if you are confident of your own reading. Every cache owner seeks to provide quality-control, as do the reviewers, but mistakes do happen.

I think it's safe to say that you should never look inside of a light pole, where the high-voltage circuits are. Nor, generally, should you stick your fingers underneath the area where the high-voltage wires come up! But "a light-pole cache" can actually be made to be a lot of fun. I've seen some difficulty-4 light-pole caches that deserved the number! Light-poles rate second only to landscaping cross-ties as, "when you see them, you assume the cache must be there." You assume it's going to be drop-dead simple. So, what's fun to do is to design a cache that is different, especially one that takes advantage of the seeker's assumptions and perhaps his or her impatience. (hee, hee, hee.... ) All in the spirit of good-natured fun and a refreshing challenge, of course! Probably the most important element of any cache is its difficulty-rating: it should always be appropriate. The seeker should ultimately receive what s/he expects.

I'm sure that, to the extent that Garmin can be persuaded to provide technical details about their formats and protocols, this will happen. Not only the Macintosh but also the Linux community would benefit... and would be willing and able to contribute resources. There is quite a lot of "reverse engineering" visible on Sourceforge already.

It seems to me that the technique described was coincidentally useful in one particular case. If you "project" an uncertain measurement out 50 feet (or any distance), how can it be 'better' than what you started with? How can it gain accuracy? I can't speak to this with any authority or experience. I don't know.

Arbor-wells are very common hiding places. The cache does not have to be extraordinarily large or small... just make sure it won't get lost or out-of-reach.

I find that the GPS's interpretation of "a magnetic compass bearing" is usually quite accurate. The almanac data on magnetic declination is usually quite close to what you will actually encounter at the site, and there is rarely any practical need to convert them to absolute-north. A compass that you intend to use with your GPS ought to be comparable in quality to one that you would use in orienteering. You should practice with it so that you can reliably obtain, follow, and check bearings to within +/- 4 degrees of precision .. which is actually fairly generous.

I think that it is quite reasonable that you should consider in advance what will happen when your cache is searched-for by a few hundred people. We have all seen "geo-trails" leading to favorite spots, although I don't know if this qualifies as permanent environmental damage. We humans, all things considered, are not too good at "walking softly" anywhere. So, if you're thinking of putting a cache in a fragile or sensitive spot, maybe another location nearby would be just as suitable?

I, too, would stick with brand names of reasonable vintage. All modern GPS receivers are sophisticated electronic devices which can be expected to give you comparable navigational accuracy -- without exception. They may vary as to speed, performance under adverse conditions, or the content of their displays ... but they will all get you where you want to go. I would not advise buying very old units. Frankly, the advice to buy "ol' yeller," or a unit like it, is pretty darned sound advice.

Even though the cache may be old and familiar and tired to you, it may well be that even tonight some brand-new cacher has downloaded information about your cache and is eager to go searching for it tomorrow. You just never know when a new member of your audience will arrive. Don't remove their fun before they have had a chance to enjoy it!

I have searched for and placed caches of all sizes... and enjoyed most of them. It's fun to find a box in the woods, but it's also fun to "palm" a <<mumble_mumble>> device right under the nose of an unsuspecting muggle. The beauty of this sport is that there is plenty of room for both pursuits. No harm, no foul. You'll find that you naturally gravitate toward the particular kind of caches that you like to find, perchace to place, and that you will simply ignore the others. This sport appeals simultaneously to hundreds of parallel threads of interest .. appealing to all of them while excluding none of them. We can all approach and enjoy this sport in our own way! And there aren't that many sports that you can say such a thing about...

Say hey, you were a "muggle" once, eh? While stealth is part of the game, this same stealth is part of the appeal of the game, even to "muggles" like you, yourself, once were! I have found, many times, that the people who were genuinely curious about what the heck I was doing ... quickly joined the sport. Just as I myself did. Just as you did! "Stealth and secrecy" are .. part of the fun. But there is always "room for one more." You should do all that you can to promote the sport and to encourage and assist others to "acquire the obsession." Just as you did.

Although the GPS system is very good at getting you close to where you want to go, remember that on a very good day it can only tell you that you are somewhere within a circle that is 20 to 50 feet wide. This is inherent in the system: it does not matter what model you own. (All GPSes can be expected to produce similar results, albeit at different speeds and with better-or-worse results under adverse conditions. They are all pretty "Tom Swifty" devices!) If the caches you are looking for are uncomplicated, urban-style caches under generally good sky-conditions, simply expect the system to get you within a hundred feet or so ... which is pretty darned good if you think about the fact that the sats are tens of thousands of miles away ... and plan to "use your wits" from there. Even though the GPS may appear to be able to "take you right to where 'X' marks the spot," it really can't. So, don't expect it to. You've got a fine GPS. You wouldn't get better results if you'd bought a different one. You made a great purchase-decision. (You didn't get :anitongue:d...) Now, get out there and find yourself some caches! Work within its technological "limits," and enjoy the sport.

Perhaps I am sympathetic to those law-enforcement officers; and to the various site managers, superintendents and so-forth. I understand their position; the job they do; "where they are coming from," whether I agree with them in every example or not. We do not live in a nice world. Not everyone whom these people encounter are "nice people like us," and sometimes it's hard to know the difference -- or dangerous to take the chance. Since we are "nice people," we can work with them. They really are "on our side," and we on theirs. Geocaching isn't a counter-culture sport. Stealthy it might be, but our intentions, if revealed (thus spoiling the fun...) are honorable and legal. We go -- or we always should go -- where we have the right to be, when we have the right to be there, and with the knowledge and consent of the property owners whose lands we enter (and whom we invite to "play along with us"). If questioned by an officer, we answer truthfully and completely. If asked to leave, we politely and immediately do so. We are here to have fun, and nothing more. We need to be mindful that some very ugly people are out there, too. And I don't mean administrators. We don't want to encounter those nasty folks either. Some of the administrators whose decisions we might not agree with, do deal with these cretins and with the damage they do. Sometimes they must [literally!] "shoot first," and believe it or not, sometimes they have to. (Uh huh, when someone cries "somebody call a cop!" ... they get called. ) When setting policy, they don't always see a way to set a policy that will allow us and to exclude them. It's their choice, their responsibility, and their authority. "The buck stops there." In lots of those decisions, everyone can't win. When faced with a decision we don't like, the first thing we all should do ... and be very clear that we are doing ... is to respect the decision and to affirm the authority of the person who made it and that we have no intention of defying that decision. We respect and work within the system. Try to understand why the decision was made. Then try harder. See if there is common-ground; room for compromise. Does the administrator simply lack information? What is his or her point-of-view? What are the constraints on their power? Be creative in looking for workable solutions (hint: that might not be as easy as you think!!), and respectfully submit them to the decision maker through due process. Honor the decision until it changes. Administrators are people too. (Believe it or not... ) As pious as this may sound, it is what I truly and sincerely believe .. and recommend.

That's what you want to place. "Take me to an interesting place that you know about but that I might not know about yet." Give me a clever find, but try to make it one that I eventually will find. Let it please me and be worth my trip. Show me that you cared about your work... so that, at the end of the day, a "smiley" will be on my face, not just a website. Rate it appropriately as to difficulty... people naturally dislike something that is "too easy" or "too hard" depending on how it was advertised. If the audience comes away frustrated or bored, you've missed your target and corrections are needed. There are all kinds of audiences out there. The cache location should be safe, well-thought-out, and so on. Once you get an idea of where a cache might be placed, you might set one up on-the-spot or you might think about it for many days. Consider how your future audience will approach the puzzle you have set; both how they might go about getting it right and how they might get it wrong. (A seeker's enthusiasm, possibly combined with inexperience, can even be potentially dangerous to them, and you need to think very carefully about that when designing your placement, your description, and your clues.) The cache must be known to the property owner. Since it may be sought at any time of day or night and in any kind of weather, these considerations must be disclosed. Property hours? High water? Is it lit at night? The list goes on... It's your show, and yours to think about. As the boilerplate says, "sometimes a good location turns out to be a not-so-good one." If your show needs to be closed down, be the one to close it. But there's an endless opportunity for being creative. When you set the cache, imagine that you're setting the table for your guest. (And cleverly hiding the table, of course.) People will come to your spot, hoping to be thereby entertained for a little while, and it will be a personal, one-on-one encounter each time between each seeker, as an individual, and you, the clever hider. I think that I enjoy hiding caches as much or more as seeking them.

Not personally owning such a GPS, I don't know how accurate it will be for this purpose. What I use is a compass which has a sight mechanism specifically designed to let you get precise bearings on distant objects. But a compass with a flip-top mirror will do well enough. The thing you need to be able to do, and to do with "+/- 4 degrees of precision," is to sight upon a distant object and be able to ascertain its bearing from you with that kind of precision. My impression of the electronic-compass features is that this is really not what those are designed to do. They'd be great, say, in a canoe or a kayak, because they'd give the GPS another independent source of bearing information (and, combined with the position data, would enable it to ascertain the presence or absence of tidal and current drift). If you are navigating cross-country through the woods, you move from one point to another, constantly shooting bearings ahead of you and back bearings behind you, to help you keep on-course. Since there is going to be some amount of error each time you repeat this process, care and precision are necessary. This is especially true when your direct-line course is blocked... by geography or obstacles or simply by a hill that you can easily walk over but can't see through. As you're walking along the bearing you've chosen, the electronic compass would be a fine reference to make sure you're going in generally the right direction. And it may well be more precise than that... I don't know, because I can't look inside the GPS and see for myself where that little needle (or ball or whatever-it-is) is actually pointing. But you need to be able to sight across it, and "eyeballs" aren't good enough for precision work. Anything can disturb the compass. For example, you should take your watch off. You should stand 20 feet or more away from any car. Since I can't see the compass needle inside of a GPS, I have no way to know if the needle is being affected or not. And, not owning such a unit, I don't have any experience with it.

The sister sport of orienteering virtually consists of the kind of backwoods direction-finding that Jeep_Dog describes, and I encourage you someday to try it. Learning how to maintain a bearing course through light or dense woods, around obstacles and so-forth armed only with a compass and a map is both great fun and a great exercise. (These days you usually have a GPS in your knapsack "just in case".... turned off.) It is truly difficult (I see now) to explain why this technique works and why it works so well, until you experience for yourself a situation where it is applicable. When you are seeking a cache where radio reception is poor, or there are no visual clues to help you pick among dozens of hiding places, then, and perhaps only then, will the value of this method truly become clear. If you are able to seek out the caches that you're looking for by following the little needle, then by all means keep doing it: it works for you. When it finally doesn't, re-read these posts. A modern GPS is a clever piece of electronics. It will work so well in many situations that it will catch you by surprise when you get yourself into a situation where it does not. For instance, the location-averaging feature... If you walked into the woods from an open clearing and entered the woods only recently, your GPS still has a lot of clear-sky readings to work with. But, if conditions have been marginal for the last twenty minutes or so of your walk, the GPS memory is full of "junk" and the little needle-display might turn out to be Wandering Willie. This is where you'll be glad to have a compass in your pocket. The reason why distant-triangulation works in conjunction with GPS is that it gives you a narrow course to set... a course that is narrower the farther away you are. But you still need to know how to set a course in the woods, and how to use a compass to make sure you're on that course even if the cache is out-of-sight of where you're taking your reading! (It should be emphasized: get well away from your car! That's quite a hunk of steel and it can fuddle your compass from many feet away...) Basic orienteering skills give you one additional benefit: they teach you to observe the woods. And they teach you how to be aware of your position, bearing and distance as you approach a distant target. This is not the same application of a compass that we use in Orienteering: this is a bearing-line in which both endpoint positions of our GPS-lines are "uncertain." But it can still be far better than what you have to work with when relying upon the GPS alone.

StarBrand, I "borrowed" your diagram, not using it as you intended but using it nonetheless. I think if you'll work through my example now .. do it on paper .. you'll see my point at last.

Thanks for the drawing, StarBrand. Let's use your drawing as being "you're fairly close to the cache," because the rectangular box you've drawn is fairly fat. First of all, blot out the "right answer," the obelisk, and the tree. Also blot out the dot which represents "where you are." You do not know: where you are, where the owner was, or where the cache is. The true extent of your knowledge is only the circles... their size and their approximate distance from one another. Nothing more!! Take a straightedge and start drawing lines at random. The rule is that each line must begin somewhere in the first circle and must end somewhere within the second one. After you have drawn a hundred lines or so ... observe the "spread" of those lines. How widely do they "fan out," from the most extreme clockwise line to the most extreme anti-clockwise line? Offhand, I'd say that there looks to be a spread of about +/- 30 degrees here... Okay, then, what does that mean? It means that there is a range of about +/- 30 degrees in what a properly functioning GPS could be telling you right now. 60 possible values, and one (but only one) of them is right. You don't know which one. But the odds that you're looking at the right answer right now (and don't know it yet) is, worst case{*}, about 1 in 60. Now shorten the box so that the two circles are adjacent but not touching and repeat the procedure. Now the spread is probably more than 80 degrees. The lines, which represent a possible solution to our problem, "fan out" much more. There are now about 160 possible values the GPS could give us: the odds of our GPS being right are now about{*} 1 in 160. Now, move the two circles so that they overlap. Now the spread becomes 360 degrees because, within the region where the two circles do overlap, a line can be drawn in any and all directions and still meet the requirement that one endpoint lies in one circle and the other endpoint lies in the other. That's as bad as it can get, of course. [ {*} Note: Your GPS receiver has lots of clever "averaging" technology designed to dampen the variance that you see... which is why you need to let your GPS "settle down." What it's doing is gathering a bunch of data-points which it is then averaged to give you the answer you see. Which is why your actual observed performance will probably be better than these worst cases.] Now, let's go the other way. Stretch the box out so that it's, say, three feet long. Once again, draw lines that start in one circle and end in the other, and observe the spread of those lines. You will see that the range of bearings is now much smaller. A properly functioning GPS will return one of these bearing values, and now, if we have a spread of (say) +/- 4 degrees, there are only 8 to choose from. The probability that our answer will be the right one jumps up to 1-in-8. The longer the box becomes (within reason) the narrower the spread will be and the better the probability that our GPS is, in fact, telling us the right answer will also be. So what does this mean? Bearings taken from a distance are more usable than bearings taken from a close distance. The closer you get to your destination, the more unreliable the answers can become. The very clever electronics in your GPS are using averaging and other fun tricks to try to make your actual observed answers better than these. Those electronics generally do succeed. Even though these techniques might be complex overkill for urban caching among obelisks and trees, there are other times when they will make a rather dazzling difference in your success. Q.E.D.!

Oh fellow gentlebeings, isn't it plain enough that you can never be more certain of the cache's position than the owner was? I never said otherwise, and never will. Every one of you, when you draw your diagrams, draws a triangle from your GPS (a single point) toward the cache area. And there's the rub: your own location is an uncertain area, too! Just as the cache owner did not know her position as a single point, neither do you! When the GPS draws a bearing-line from "where you are" to "where the cache is," it is necessarily estimating "where you are." You do not visually see this on your GPS so it is very easy to overlook it. It is easy to treat the problem as simply, "the bearing I see on my GPS is 'off' because I do not know where the cache is. I know where I am (wrong!) but not where the cache is..." Wrong. Both points, on each end of the projected bearing line, represent uncertain, unknowable positions. Not just one of them (the cache position), but both of them. In Markwell's graphic above, put the GPS inside the blue circle at the upper left of the graphic: the GPS could be anywhere inside that blue circle, just as the cache could be anywhere inside the orange one, and give you exactly the same reading. Markwell's graphic is drawn as though the position of your own GPS could be known with certainty; in other words, as though the problem had one degree-of-freedom rather than two. How do you reduce the influence caused by the fact that both positions are unknowable? Separate the endpoints, as far away as you reasonably can. Take bearings that are distant, and rely upon your GPS bearings less-and-less as you approach. When you get to the point where both you and the cache are "inside the circle" that is drawn on your GPS screen... stop relying upon your GPS pointer. It works.

There are many things besides technology which makes a cache fun to look for. A challenging, clever "hidden in plain sight" (HIPS) hiding device, for example, is one thing I particularly enjoy. (I like to swap stories about clever hiding techniques or inventive caches, even if I'll never get the chance to visit them.) Locations of historic significance, or obscure places in one's own town that you drive by every day but didn't know about, are also of particular interest to me. This is reflected in the caches that I set and that I find. The beauty of geocaching as a sport, to me, is that it really comes down to a personal, one-on-one challenge "from the cache owner to you." When someone finds one of my caches and says that it was devious, or that s/he didn't know about this place until now... I smile and say, "You're welcome!" Each person who enters this sport can find a particular niche that they enjoy. For some people, that's "getting numbers," whereas I personally am rather disinterested in that. For some people, that's having a walk in the park with their children and family, or a hike in the woods. To each his own.

For the third time you have refused to answer, “Yes my methods gets me closer to the cache than I can get with my GPSr alone,” or “No my methods cannot get me closer to the cache than I can get with my GPSr alone.” Apparently you are unwilling to answer this simple straightforward question. Why is that? Confrontational, aren't we? The answer, quite plainly enough, must be "yes." The main thing is that a compass is not as subject to tree cover, nearby buildings or towers, etc as the GPS. The ability to do "back-bearings" to confirm that you are where you wanted to be also helps. We were active in orienteering and route-finding long before GPSes were public and enjoy mixing the two technologies; finding this very useful. "O" fans have been using these techniques in the woods long before the first Navistar satellite was launched! (Obviously, the fact that we are using GPS is an adaptation of those techniques.) Look once more at the overlapping-circle (Venn) diagram above, then ponder what would happen if the two circles, instead of being overlapped like that, were a few hundred feet apart. Consider only the influence on the bearing figure; ignore the distance. The "possible bearing to the target" is small at a distance; grows larger as you get closer; becomes a full 360-degrees in the orange (overlap) region of the diagram above (the exact size and orientation of that area being, as the artist did note, arbitrarily depicted on that diagram). In the other diagram, the one showing incoming bearings as triangles that overlap the circle... consider that these shapes are actually rectangular. (You don't know exactly where you are, hence the apex is not a single known point.) The farther away you are, the more those rectangles approach being triangular and can be considered as though they actually were triangular. You will not get a figure that is closer or more certain than what the cache setter was able to obtain, but you will obtain a figure close to it, which is a considerable improvement. As has been stated, if it was too easy, we would probably switch to a different sport/pastime/hobby/game ! Cache on! By whatever means works best for you!

Actually, I believe there are caches like that out there. (Lots of hams, like myself, in this sport.) Apparently there are also caches you can only find with a wireless-enabled PC running specific software. "Too much time .. on my hands .." -- Styx

Take the beautiful graphic from two posts ago, now, and draw a second gray circle, slightly overlapping the first. This is the error concerning your present location. The cache owner promises that the cache is somewhere inside his circle... but are you actually inside the owner's circle yet? This is what you do not know, and this is where the second degree of uncertainty arises. On the average, the two circles will overlap by some amount, so a 30-foot owner's circle might expand to only a 50 or 60-foot search area. The two sources of uncertainty blend in with one another to some degree. But you are still searching an area larger than you could. And once you get in that area, following that little pointer, guess what! Once you get inside the circle, every one of those 360 degrees is equally probable. The pointer reading is meaningless. If it does not appear to be so, consider this: you could be relying, without even knowing it, on some of the averaging-data that your GPS has accumulated as you walked in a straight line. Have you ever noticed that your GPS seems seems to become more uncertain the longer you pace back and forth like that? For many caches (and, heaven help us, light-poles...) there is a lot of ancillary information that you can draw upon. If you see an obelisk and a large tree, and nothing else, then you probably don't need the additional information. Heck, you can leave your GPS in your car. But what if the area is a riprap pile of stones at the edge of a river, hundreds of feet long, and in that area you are searching for one fake rock... I have answered the question and will repeat it once more: The purpose of the triangulation technique is not to make the owner's area smaller than it is; nor to divine what cannot be known. (These are technological limits of the GPS system, period.) What it does do is to reduce the amount of area that you will otherwise find yourself searching, reducing the area to approach that of the original. To repeat: It is not possible by any means to determine whether the cache lies under that obelisk or under that tree. What triangulation can do is to limit your search space so that it is no-larger or not-much-larger than that gray circle. The proof is in the puddin'.... try it for yourself. If you don't want to, or if you routinely search for caches where the location is self-evident once you get there, fine! There are plenty of caches out there like that. But the caches I place, and the ones I love to find, are not like that. The caches I love to find don't have visual clues. In my neck of the game, the cache might be in a film-canister with a fake piece of grass glued to the top, sitting flush to the ground. And this is where your compass might come in handy. When people go out caching with me, I notice that they start following me, because I'm not wandering: I'm walking, purposefully, in a straight line.

Ahh, I guess the point is subtle after all. There is a difference. Without triangulation, you, who do not know your own position within (say) 50 feet, are looking for a cache whose position is also not known within (say) 50 feet. You assume you know when you are "10 feet out," but you don't and you can't. This point cannot be over-emphasized! This is what misleads people: one is taking at face-value a piece of information that cannot be known at face-value. One is using a measurement that in fact describes the approximate center of a region of some size, as though it were a description of a single point. It is not. Since you cannot eliminate either source of uncertainty, you compensate for it, employing the available information in a different way. Reliance upon angles from a distance, rather than location-indicators and map-pointers, will yield markedly better results. A high-quality compass is needed, with careful attention on how you are using it, since "+/- 4 degrees" is not a very large spread to measure. I simply encourage you to try it for yourself.

CoyoteRed, you are saying exactly what I mean: tighter tolerances. Nothing can make the owner's GPS information more accurate than it is. You cannot calculate either the right answer or a better answer by any means. No matter what you do, this uncertainty will always remain. (Cache owners strive to minimize it.) I didn't want to dive into trigonometry and I don't want to dive into the mathematics of probability, but this is a probability-problem. Nothing will ever change the essential nature of the problem, which is of course one of the challenges of our sport. You're faced with a problem with two degrees of uncertainty; now, here is a useful method that reduces it toward only one. What distance (and triangulation) does do is this: it helps to factor out the effect of your uncertainty as to your own position! Your readings will not "vary widely" as they do when you get close; they will be consistent. It is a bit unfortunate that GPSes tell you not only "you're X feet away," but "you're X feet away in Y direction." Once you get "inside the circle," both pieces of data are bogus. Use the information from a distance, and when you get closer, put your GPS in your pocket. --- btw: I realize that what I am explaining is a bit difficult and that I may not be explaining myself clearly, but I'm not "refusing" anyone or being evasive. (Nor, particularly, trying to be some know-it-all!) "It works for me, and here's why; hope it helps!" Other fellow cachers, please chime in!