Jump to content

How do I use a compass to find the cache? can I?


tweetiepy

Recommended Posts

I hate when I stop to check the GPS that it goes all wonky on me or when I'm in a wooded area trying not to get snapped in the face by a branch and the GPS stops leading me in the right direction.

 

I want to see if I can get some assistance from the compass. However, I'm also a compass newbie and not sure how it works. Can I use the compass to find the cache and what, exactly, do I need to do to set it to the correct coords (I have no idea how to do that)

 

I don't necessarily have a map (apart from google map) to be able to set the compass either.

 

How do I go about doing this?

 

Thanks in advance for your help

Link to comment

Since you mention a map, I am guessing you mean a "real" compass instead of the one in your GPSr?

 

You'd need a topo map with the location of the cache marked on it, and then you'd need to be able to triangulate your current position in the field (or use the UTM coords from a GPSr reading) to mark where you are in order to get a bearing. Then you'd also have to make sure you were taking into account the declination for your area, and knew the size of your paces to gauge distance, and so on. The good thing about the compass on your GPSr is that it knows where the cache is relative to where you are, whereas a dumb compass (as opposed to a smart one?) has no idea where you are.

 

If you mean the compass on your GPSr...follow the arrow???

Link to comment

Not my GPS compass, I mean a "manual" compass

 

What's are UTM coords? Do you mean the N/W coords off the GPS/cache page?

 

I wasn't lying when I said I'm a total compass newbie (I checked online to see how to read a compass from an actual paper map but I'm clueless on how to use it to get to the cache)

 

I mostly want to use it when the GPS goes wonky

Link to comment

It is so, so complicated... :unsure:

 

I have had to teach this to Scouts as part of the geocaching badge...the problem is that for me, at least, using a topo map and marking where I am versus where I want to go is not accurate. So...for example...I have my map, and I have the coordinates for the cache. Before heading out, I look at the UTM conversion of the coordinates for the cache (available on the cache page)--UTM is basically a grid overlay with a different numbering system. Topo maps have square grids, but these are usually 7.5 minute grids, or about ten miles. There are no markings more precise than that...which is where the military, UTM (Universal Transverse Mercator) grid comes in. You get a separate tool--a little square of plastic--that is the size of a standard topo map grid, so that you lay it over the map, and it you can make tick marks at the lines and draw a more precise grid. These take you down to about a one square mile grid, and you need to actually draw them on your map. THEN you need to break that down even further in order to have any accuracy whatsoever, because you want to be closer than a mile to the cache. :P And then (waaay too complicated to explain here) you'd need to learn how to plot the UTM coordinates of the cache and mark it on the map. That is all before you head out!

 

So say you're hiking around in the woods, and for some reason you lose your GPSr signal, or it goes wonky, or the batteries die and you have no more. So you break out the compass...except...where are you? You know where the cache is, but in order to navigate to it, you would need to know that it is, for example, northeast of you, and be able to figure out an exact bearing (in degrees). But you still don't know where on the map you are! So you must then find three landmarks that show up on your topo map--mountain peaks, etc. You can take a bearing by holding your compass up and sighting along it toward the landmark, then draw a line on the map at the same angle. Do this two more times with two other landmarks, and where they cross is where you are standing.

 

Then you must place the compass onto the map (this is why they are usually clear plastic) and draw a line from the cache to your location. Then, that line will show through your compass (with the dial turned so that north matches north on the map, not IRL) and will point to, in this example, say 40 degrees. You'd hopefully have your compass' declination already adjusted (too complicated here), and then could hold the compass up again and sight a landmark you can see at 40 degrees, then walk to it, sight another landmark, and so on. BUT, you also need to know HOW FAR to walk in that direction in order to reach the cache, which is why you need to know how many paces you take in 100 yards (or however you want to count it).

 

You would then wander around and get lost.

 

I hope that gives you an idea of how complex it is...there's not really a good way to teach this in a post...I know people DO use a map and compass to find caches, and the more power to 'em.

 

But remember that the entire idea of geocaching started when people didn't have to rely on maps and compasses anymore...

Link to comment

If your GPSr is sometimes wonky, it might end up pointing you incorrectly when you set the compass...if you want to try it, stop at some point when you think it's got a good reading (you'd have to set it to show "North Up"), and then see where the GPSr points. Then turn the dial on the compass until the degrees you want match the bearing arrow (the one drawn on the plastic) at the front of the compass. Then turn your body until the inner red arrow lines up with the arrow on the compass casing. You'd get: red arrow lined with the marks on the compass, with the number on the dial matching your degree bearing. You are now facing the cache. You'll still want to look up and pick a landmark--tree, pile of rocks, a McDonald's--that is in that direction to walk toward; if you keep looking down at the compass while walking, you will meander like an old stream. So you pick something at your bearing, walk to it, and pick another tree to walk toward, and so on. The problem is that you still have the issue of distance to walk in that direction, unless you're very good at estimating.

 

You can always play around with it and see if it works...use the compass to get to where you think the cache is, then take out the GPSr and look at it and see if it agrees...

Link to comment

Navigating with map and compass is a skill that takes a great deal of training and practice. The compass alone won't be very useful. Military personnel spend a great deal of time learning this skill. Not saying it can't be done, but the GPS makes it SO much easier.

 

Maybe we can focus on why your GPS gets "wonky" and try to remedy that. What make and model are you using? And under what conditions does it get wonky? Maybe it's as simple as changing a setting.

 

I know I had fits for awhile with my Oregon 550 until I realized that I didn't have it set up correctly to switch from Road mode to Off Road and it kept trying to direct me back to the nearest road.

Link to comment

It is so, so complicated... :unsure:

 

I have had to teach this to Scouts as part of the geocaching badge...the problem is that for me, at least, using a topo map and marking where I am versus where I want to go is not accurate. So...for example...I have my map, and I have the coordinates for the cache. Before heading out, I look at the UTM conversion of the coordinates for the cache (available on the cache page)--UTM is basically a grid overlay with a different numbering system. Topo maps have square grids, but these are usually 7.5 minute grids, or about ten miles. There are no markings more precise than that...which is where the military, UTM (Universal Transverse Mercator) grid comes in. You get a separate tool--a little square of plastic--that is the size of a standard topo map grid, so that you lay it over the map, and it you can make tick marks at the lines and draw a more precise grid. These take you down to about a one square mile grid, and you need to actually draw them on your map. THEN you need to break that down even further in order to have any accuracy whatsoever, because you want to be closer than a mile to the cache. :P And then (waaay too complicated to explain here) you'd need to learn how to plot the UTM coordinates of the cache and mark it on the map. That is all before you head out!

 

So say you're hiking around in the woods, and for some reason you lose your GPSr signal, or it goes wonky, or the batteries die and you have no more. So you break out the compass...except...where are you? You know where the cache is, but in order to navigate to it, you would need to know that it is, for example, northeast of you, and be able to figure out an exact bearing (in degrees). But you still don't know where on the map you are! So you must then find three landmarks that show up on your topo map--mountain peaks, etc. You can take a bearing by holding your compass up and sighting along it toward the landmark, then draw a line on the map at the same angle. Do this two more times with two other landmarks, and where they cross is where you are standing.

 

Then you must place the compass onto the map (this is why they are usually clear plastic) and draw a line from the cache to your location. Then, that line will show through your compass (with the dial turned so that north matches north on the map, not IRL) and will point to, in this example, say 40 degrees. You'd hopefully have your compass' declination already adjusted (too complicated here), and then could hold the compass up again and sight a landmark you can see at 40 degrees, then walk to it, sight another landmark, and so on. BUT, you also need to know HOW FAR to walk in that direction in order to reach the cache, which is why you need to know how many paces you take in 100 yards (or however you want to count it).

 

You would then wander around and get lost.

 

I hope that gives you an idea of how complex it is...there's not really a good way to teach this in a post...I know people DO use a map and compass to find caches, and the more power to 'em.

 

But remember that the entire idea of geocaching started when people didn't have to rely on maps and compasses anymore...

From that explanation of compass use, I guess that a compass constitutes "specialized equipment" used on 4.5 & 5.0 difficulty caches! Mind-boggling!

 

:blink:

Link to comment

The wonky issues come when I stop walking or if I'm in a wooded area - the GPS needs to be moving to get an accurate reading.

 

I'M using a Magellan Exploris 310. There's a road mode & an off road mode? The road mode would make it easier to actually get to the cache.... Need more info please

 

Thanks for the compass info, I'll see how I manage this weekend

Link to comment

I would suggest using the technique of choosing a landmark and navigating to it. Don't stare at your GPS. When you have good accuracy, look in the direction your arrow is pointing and choose a landmark that is straight in front of you. Walk to it. Check your GPS and choose another. Repeat as needed. Also stay on the trail if it is going in the right general direction.

Edited by Team Taran
Link to comment

 

From that explanation of compass use, I guess that a compass constitutes "specialized equipment" used on 4.5 & 5.0 difficulty caches! Mind-boggling!

 

:blink:

 

That is totally ignoring the GPSr and only using the compass, and out in more remote locations...From what I've seen, puzzle caches or multis give a bearing and distance from coordinates that you find with your GPSr, so it's a simple matter of standing in the right spot, finding the bearing, and walking however many feet to the next coords/final. Which is not difficult at all...and usually within a couple hundred feet at the most.

 

Which...if the OP were getting that close with his GPSr, it probably wouldn't be an issue.

Link to comment

You should see this video....

 

Yep, yep. Notably, he always knows where he is on the map, so can find his bearing toward the cache (or from a landmark, ie the tip of the lake) with no problem. If you've been walking in the woods for twenty minutes and then put the GPSr away, you're lacking that crucial starting point. And printed satellite maps are great, unless you're in a big forest where it's just a swatch of green treetops...

Link to comment

The wonky issues come when I stop walking or if I'm in a wooded area - the GPS needs to be moving to get an accurate reading.

 

I'M using a Magellan Exploris 310. There's a road mode & an off road mode? The road mode would make it easier to actually get to the cache.... Need more info please

 

Thanks for the compass info, I'll see how I manage this weekend

.

 

OK, that gives us a couple of clues. Both my GPSr's are Garmin and I've never used the Magellan, but checking out the specs on the 310 I see that it does not appear to have an electronic compass. It determines your direction of movement by constantly updating your position. So you are correct in saying that when you stop moving, or stand in one spot and turn around, it seems to get confused as to which way is which. All that is needed to get it oriented again is to start moving. So if you think you are close to GZ, you may have to walk away about 50 feet or so and approach the spot again at a good walking pace.

 

Higher end units have. 3-axis electronic compass which does not depend on motion to know which way is which. You stand in one spot and turn around, the pointer will continue to point to the waypoint you are navigating to. That's one feature that prompted me to upgrade from my old Etrex Legend HCX to the Oregon 550.

 

That's not to say the Explorist 310 isn't a fine unit for Geocaching, because it is. You just need to understand the basic difference between GPS's with an electronic compass and those without.

 

Now, I'm not sure if the 310 supports routable maps....that is, turn-by-turn driving directions. I don't think it does, similar to my old Etrex. It just points you in a straight line to the waypoint. So I don't think any confusion between on-road and off-road modes comes into play here....it's always off-road.

Link to comment

I am also a beginner with an eXplorist 310, like the original poster. No, it has no magnetic compass, and does not do turn-by-turn routing so that isn't an issue ("off-road vs road").

 

The 'compass' in the 310 seems OK as long as you are moving in a straight direction... at a steady pace... and hold it steady... etc.

 

I don't know if this is related to the OP's question - sorry if it is off topic, but maybe not. I have my GPS, which is working, and the GPS tells me the cache is 50 feed NNE. I also have a compass - in this case, my wristwatch has a built-in compass. So I can use my 'real' compass to direct me to the cache, per the GPS directions, NNE, right? Even if I'm standing still or my GPS compass is otherwise not behaving, correct?

 

I think it should work, because even if I'm standing still, the GPS knows where it is, and it knows where the cache is, and it knows where North is on its map, so it should be correctly reporting the bearing (right word?) to the cache. Does this make any sense?

Link to comment

During a period while the compass in my Etrex 30 was not working reliably, I turned it off and carried a real compass. I don't use the compass screen in the Etrex anyway, I prefer the map screen with the overlaid pointer and distance indicators. By setting the map display to 'North Up' and then orienting the device itself to face the way that the actual compass said was North, the GPS arrow would always point in the direction that I needed to go. On rough signal days or areas, I still often compare the GPS compass to a real compass. I find that the electronic compass is more easily mislead by stray magnetic fields and power lines than a traditional compass, so it's a good idea to have a compass as backup or reference.

 

Try running with a map display set to North Up and direction/distance overlays to see if that helps cut down your problems with 'arrow bounce'.

Link to comment

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...