How close is close enough?

[+FireRef]

I have been on a couple of cache hunts so far, and when I looked on the website, they reference an "offset" cache. I assume that otherwise, the coordinates that are given for a cache are supposed to be very close to where the cache actually is. Accounting for the 3 meter varience in the GPS signals (more depending on the quality of the signal), what is considered "close enough"? I have had some trouble finding some caches, because they are 15-20 feet or more from the actual area my GPS says is right.

[+opey one]

All have variations. In some cases the difference has been in the hundreds of feet range. A fifteen feet search area? Not too bad.

 

This is where a previous thread came from, as I have encountered once, the Etrex to come closer than my Magellan 310. Etrex within five feet and mine at the calculation of hundredths of a mile to feet equaled sixteen feet.

[+briansnat]

I'm not sure what you are asking. A GPS will get you, under normal conditions, to within 15-30 feet of the coordinates. The cache placer also had the same margin of error when they placed the cache, so potentially, under the best conditions, you could be as much as 60 feet off. Possibly more if the sat alignment wasn't great when owner placed the cache, or while you were looking. There are also other variables, so I've found coordinates to be as much as 150 feet off. Granted this is rare, but it can happen.

 

If you are expecting your GPS to lead you directly to the cache, then forget it.

 

A true "offset cache" is slightly different. An offset cache will send you to a specific spot, and from there clues will guide you to the cache. The actual cache is usually close by, but it could possibly be miles away.

 

"It has been my experience that folks who have no vices have very few virtues" -Abraham Lincoln

[+georgeandmary]

quote:

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Originally posted by drinkeii:

I have had some trouble finding some caches, because they are 15-20 feet or more from the actual area my GPS says is right.

---

 

The more you cache, the furthur your definition of close is. Less than 30 ft isn't horrible, but more than that and you tend to question the readings. But still, 50 ft off isn't unfindable. Even furthur.

 

george

 

Pedal until your legs cramp up and then pedal some more.

[+opey one]

Hey BrianSnat!!!

 

You seem quite informational on several if not all of your posts, so I'm gonna add to this one a little.

 

What could be the outcome of two different units, say a Magellan and Garmin, where the Magellan offers location rounded to the nearest hundredth and the Garmin located to the nearest thousandth?

[+The Leprechauns]

BrianSnat is busy, and asked me to respond on his behalf. The answer to your question is, if you have a Garmin in one hand and a Magellan in the other hand, and a newspaper reporter is accompanying you, then the outcome is a "not found" log.

 

x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x-x

.sdrawkcab dootsrednu tub sdrawrof devil si efiL

[+opey one]

Hey, thanks Leprechaun! That really cleared that one up!

[+worldtraveler]

quote:

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Originally posted by The Leprechauns:

...The answer to your question is...

---

Huh? I thought the answer somehow involved a monkey with a brick. How did we get such different answers? I'm using a Garmin; could that account for it?

 

Worldtraveler

[+FireRef]

Thank you very much - this must have been a misunderstanding on my part I appreciate the replies, and think this is going to make me have a little more fun going after these, rather than just being irritated because it isn't where it was "supposed" to be!

 

Dave

[+opey one]

BTW, what GPS unit do you use drinkeii?

 

In my case, I have a low end model Magellan 310 which has performed greatly.

 

Call me stupid (I don't EVEN want a reply from UMC, but am sure one will come), but when in extreme tree coverage or cliffs, the reading seems to bounce around, giving a false reading, if you will.

 

So, I tend to run, if the area will allow me, or briskly walk, and that seems to get a better average.

 

Does anyone else have better accuracy the quicker they move? Darn right you do!

 

Keep up the good work and you will find the results you are looking for, drinkeii. Glad to have you with us.

[+Dave_W6DPS]

I had the same general idea when I started. "My GPSr says right here, so why is it over there?"

 

I try to get to where my GPSr nulls out. You can see this when you stand still and the cache seems to be circling you a few feet away, or you follow the nav arrow and is keeps suddenly jumping to another direction when the distance gets below 15 to 20 feet.

 

When I get to the null, I put my GPSr in my pocket, and take a good look around. If I don't see the cache (about 20% of the time I have) I look for places I would hide a cache. Checking those out works another 60% of the time, roughly.

 

If I still haven't found it, I start back at the null point (which has usually shifted a bit by this time) and start walking in expanding circles. If I get 50 feet or so away without finding it, I decode the hint.

 

It has been a dozen or so since I needed the hint.

 

You will develop a "feel" for finding them is you keep at it. Don't let it get you down, we all have a learning curve. If you are doing it right, you should keep learning and having fun.

 

Good luck!

 

Dave_W6DPS

 

My two cents worth, refunds available on request. (US funds only)

[+TinSparrow]

quote:

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Originally posted by opey one:

BTW, what GPS unit do you use drinkeii?

 

In my case, I have a low end model Magellan 310 which has performed greatly.

 

---

 

I also have a Magallen 310. It's a low end no frills unit, but the reception is so good that I can use it on airplanes. For a while I owned an eTrex Venture as an upgrade unit, but the eTrex would lose signal at the suggestion of trees in the area. I finally returned the eTrex and picked up a Magellan Meridian.

 

You had mentioned earlier that the Magellan's only showed position to hundreths of a minute, but this is only true on the Magellan 310. Every other Magellan unit that I have seen expresses accuracy to thousanths of a minute. In most cases, accuracy to hundreths is all you need for search caches.

[briancm]

Depending on how many sattelites are available and whether or not I have WAAS lockup, I have seen my GPS report accuracy between 157 and 10 feet. That means a circle 100yds across at worst. You also don't know if the GPS which was used to read the initial coordinates was an older model, with less accuracy and problems aquiring satellites.

 

I just found my first cache, and it took two trips. After the first trip my pants were covered with grass and leaf stains. Discretion nothing! I was beating those bushes! On the second trip I found the cache because someone else hadn't rehid the cache like it had been hidden.