GPS confusion

[rebeccatx]

I've been out a few times now, found two. I have an Garmin etrex Venture HC, on recommendation from this site, thank you very much. However, what's the deal with mixed messages? Last night it couldn't decide what to tell us. Standing still it would change from "Dist to Next" from 0 to 9 feet, and the compass pointer re-fixing in different directions. Out in the open, no tree cover, no storm brewing. And also, you all don't actually dig a hole and bury a cache do you? Thanks, we're about to give up.

[cliff_hanger]

I've been out a few times now, found two. I have an Garmin etrex Venture HC, on recommendation from this site, thank you very much. However, what's the deal with mixed messages? Last night it couldn't decide what to tell us. Standing still it would change from "Dist to Next" from 0 to 9 feet,

 

That's actually very good. Expect that your GPSr will get you to within "about" 30 feet of the cache on a "good" day. After that, you have to use your eyes and geosense. Think "where would I hide it?"

 

and the compass pointer re-fixing in different directions. Out in the open, no tree cover, no storm brewing.

 

Venture HC does not have a magnetic flux compass. The compass relies on satellite information. Thus, you have to be moving for it to function. Other units like the Legend HCx and Vista HCx have magnetic compasses that kick in when you stop moving below a certain speed and switch from satellite compass to magnetic compass.

 

And also, you all don't actually dig a hole and bury a cache do you? Thanks, we're about to give up.

 

No, caches are not supposed to be buried in the sense of digging a hole. However, they may be covered over with sticks, rocks, leaves or other debris.

 

Don't give up. To start with, look for caches that are large containers. It's the hunt, not the find.

[cliff_hanger]

double tap (sigh)

Edited June 17, 2008 by cliff_hanger

[+admo1972]

If it is saying 0 to 9 feet, that is as good as it gets. That simply means that the unit thinks you are at the same spot the cache is also at. Keep in mind, the accuracy is important. At best, it can anlo be accurate to about 9 feet. That leaves the cache being up to 18 feet in any direction. Additionally, the hider had similar inaccuracy, so at best the you can be standing on the cache, or it can be 30 to 40 feet in any direction. Basically, when it says you are there, it is time to search. Look for likely spots.

 

Your unit doesn't have an electronic compass. You will notice that if you stand still, the arrow may swing around. This is due to it having no idea what direction you are facing. If you move relatively quickly, in a straight line, then the arrow will point you correctly in the direction of the cache.

 

If you have fields on the navigation screen, I suggest you have one to display accuracy. That way you will know if it has a good lock or not. If it says you are 2 feet away with 9 foot accuracy, you've got a nice GZ and start to search. If is says you are 2 feet away, but 76 foot accuracy, it may be time to wait to see if it can get a better lock. I also suggest you have the second field on the screen to display bearing, in degrees. That way, even if you stand still about 100 feet from the cache, the pointer may swing, but the bearing should stay roughly the same. Using a standard compass, you can sight a bearing if your needle on the GPS is swinging around too much.

 

lastly, Caches should never be buried. I've only comes across 2 or so that may violate this rule, but in those cases at least part of the cache was above ground. Perhaps they were put in already existing holes. But generally, caches aren't buried. They can, however, be waaaay above you head.

[Kenshi Clay]

cmon now..where would the fun be in your gps telling you with pinpoint accuracy where the cache is? part of the fun is finding it...it's an accomplishment when you do. no gps available to us in the general public can pinpoint a location. Just know that when your gps technically tells you you're zero'd in, start looking within a 30ft radius, with you at the center of the circle. What i'll do is i'll start looking when my gps tells me i'm still 30-35 ft away.

[+maurycy]

Start with caches with 1/1 (difficulty/terrain). Once you get the idea on how they are hidden, what to look for, move to next difficulty level. That's what I did and so far I am not giving up even I had 4 DNFs out of 30 caches.

[+briansnat]

That's quite normal. First off the Venture HC doesn't have a magnetic compass so you have to be moving for it to know direction of travel. If you are standing still or walking very slowly the pointer will act strangely because it doesn't know which direction is which.

 

0-9 feet is actually quite good. It's not unheard of for any unit to fluctuate a lot more than that. I've seen mine fluctuate by over 100 feet while standing still, due to signal bounce (aka multi-pathing errors).

 

Also, you're probably concentrating too much on getting it to read 0 feet. Your unit has a margin of error of 10-30 feet. So did the unit of the hider. So the cache can be 30, 40, 50 or more feet from where your unit says it is.

 

The GPS will get you close. It's up to you to do the rest. It wouldn't be much fun if it put you right on the cache. The hunt is half the fun.

[+StarBrand]

All of the consumer grade handheld units have a general accuracy around 20 feet. Sometimes a bit better, sometimes a bit worse. The reported accuracy on the unit is known as an EPE (Estimated Position Error). Remember it is only a best guess - not a statement of fact.

 

If the unit says around 9 feet - it means you have gotten about as close as the unit is going to get you. However, you have no idea whatsoever how far off the hider's accuracy was at the time of placement. So keeping the 20 foot rule in mind - add yours and the hiders together and you might have to search p to 40 foot from where your unit gets a zero. Often you will find it much closer but do be be prepared to search more.

 

Stick to regular sized caches rated 2 or less for your first few and don't give up. Think like a hider and look for anything likely to be a cache. Think vertical - not all caches are on the ground. Have fun at it!!

[+NOV8TR]

One way around the “swinging compass” dilemma, is to not use it! Because I started geocaching with a car nav system (which did have a compass mode, but was not very easy to use), I learned to just use the “raw coordinates” to find ground zero. Now, even though I use a dedicated hand held geocaching tool (Garmin Vista HCx), I still only use the extra navigation tools (compass and routing lines) to get me close (30 or 40 feet depending on terrain). Then I just make a mental note of where North is, and use the raw coordinates displayed on my compass page (or sometimes the satellite list page) to adjust my indicated location to the posted coordinates of the cache. When the coordinates of my location match the coordinates of the posted cache, I put away my GPSr, and start looking. I does not matter what the circle of error is, or “how far” the GPSr thinks it is from the cache. When the coordinates match, you are as close as you are going to get under the current conditions (sometimes that is 0 feet, and sometimes that is 30 feet,,, I.E. circle of error). It will not take you very long to figure out what 1 digit in the coordinates means in “ground distance”. I have my GPSr set to display DDD.DDDDD rather than DEG,MIN.DDD. It does not display more accurate readings this way (chipset, antenna location, and software determine that), but it does make more sense in my head to work on a simple decimal system, rather than a 360° + 60 increments + 100 increments system (Degrees, minutes, 3 decimal places). In my case, 1 digit of the coordinates equals about 1 ½ to 2 steps on the ground (N 34°). I still do the “drunken bee dance”, but this way I can spend more time with my eyes off of the GPSr, which enables me to do a better job of checking out the surroundings. More often that not, I’ll spot the likely hiding spot before I even zero out the coordinates of the hide.

[rebeccatx]

OK. Thanks. Everyone is saying the same thing. There is nothing wrong with my GPS and I need to develop some patience. You also explained how it can be that the waypoint directs me to an open grassy area with no place to hide something, the trees 10 feet away are the logical answer. Thanks.

[Kenshi Clay]

yes, i only have a handful under my belt (8) but i've learned a lot in those 8, considering most of them have been either long hikes, or hidden in forests or places w/ heavy canopy cover, and what not.

 

Patience is the key. And what I learned is that the GPS is just a tool to help you get CLOSE. it's up to YOU still to train your eyes and senses to be able to spot possible hiding places. And when it comes to accuracy, ya, some common sense as to potential hiding places become developed over time. I learn a little bit more everytime I go out.

 

Remember: GPS = Tool...in the end it's YOU that finds the cache, not your GPS.