TRUE navigation

[+climbingcrew]

I have no idea what to do when I see these in cache descriptions. I can't search TRUE on this site as it is only 4 characters, so I apologize if this has been covered recently.

 

Could someone please explain to me how to do this or link me somewhere that will.

 

Thanks!

[+The Blorenges]

Could you give us a link to the cache, or its GC number, please?

 

I'm guessing that it wants you to follow a compass bearing, or something similar, but we need some more details.

 

MrsB

[+steve p]

Can you post an example of a cache with that in the description? Maybe someone else will know right away what it is, but I have no idea what "TRUE navigation" means.

 

edit to add: I think MrsB is probably on the right track. Is this a puzzle cache that has you go on a true compass bearing from a certain point? Maybe you need a compass and have to know the local magnetic declination to convert the true bearing given in the description to a magnetic bearing.

Edited September 2, 2009 by steve p

[+climbingcrew]

This is the one that I can recall off the top of my head, and it does happen to be a puzzle.

http://www.geocaching.com/seek/cache_detai...8f-db2b199e3342

 

It is this part in particular in which I don't understand what to do.

 

This position will take close to the shoreline, but a little on the wet side. From this position proceed on "SBR" degrees TRUE for "PM" yards. There will be a double trunked tree there. Inside the hollow crotch, there is a small canister with the instructions for the final waypoint.

 

I appreciate your help

[+doingitoldschool]

This is the one that I can recall off the top of my head, and it does happen to be a puzzle.

http://www.geocaching.com/seek/cache_detai...8f-db2b199e3342

 

It is this part in particular in which I don't understand what to do.

 

This position will take close to the shoreline, but a little on the wet side. From this position proceed on "SBR" degrees TRUE for "PM" yards. There will be a double trunked tree there. Inside the hollow crotch, there is a small canister with the instructions for the final waypoint.

 

I appreciate your help

 

From what you have described, TRUE means in relation to true north, as opposed to magnetic north. True bearings are based on the actual north pole, while magnetic bearings are based on the magnetic north pole, which is now somewhere in the Northwest Territories of Canada.

 

If you are using your GPSr as your compass, you can make sure that it is set to "TRUE". If you are using a magnetic compass, then you have to so some math, depending on where the cache area is, which I can't really help you with!

Edited September 2, 2009 by doingitoldschool

[+ras_oscar]

If you get a local USGS quad map it will have a little diagraom in the corner that shows the angle between true and magnetic north. Called magnetic declanation, I think. It will also give an "annual declination" you take the declanation in the diagram, add the annual multiplied by the number of years since the map was published and get true. Here's an example:

 

magnetic declination 2004 2.5 degrees

annual declination 004 degreees

 

Required TRUE bearing 227 degrees

 

227 plus 2.5 +(.004 X 5 years)=229.52 equivelant magnetic bearing

[+climbingcrew]

I'm pretty sure that my gps does not have an option to set it to TRUE garmin nuvi.

[knowschad]

I have no idea what to do when I see these in cache descriptions. I can't search TRUE on this site as it is only 4 characters, so I apologize if this has been covered recently.

 

Could someone please explain to me how to do this or link me somewhere that will.

 

Thanks!

 

 

Not sure what you're asking. If you want to search for the word, "TRUE" on this site, you need to use a search engine like Google, using the "site:" keyword, because, as you say, the forum search engine requires words to be 5 characters minimum.

 

 

site:http://forums.Groundspeak.com/GC TRUE

 

 

Will return a list of all forum messages with the word TRUE in it. There are plenty!

[+steve p]

If you get a local USGS quad map it will have a little diagraom in the corner that shows the angle between true and magnetic north. Called magnetic declanation, I think. It will also give an "annual declination" you take the declanation in the diagram, add the annual multiplied by the number of years since the map was published and get true. Here's an example:

 

magnetic declination 2004 2.5 degrees

annual declination 004 degreees

Required TRUE bearing 227 degrees

227 plus 2.5 +(.004 X 5 years)=229.52 equivelant magnetic bearing

Remember that not every location has a positive declination that is added to magnetic. Some areas will have a negative declination that must be subtracted.

[+doingitoldschool]

I'm pretty sure that my gps does not have an option to set it to TRUE garmin nuvi.

 

If you have a nuvi, it is more than likely set to true north as a default, and I doubt you can use it as a compass. Almost every hand held GPSr, with the compass feature, has the ability to switch back and forth.

 

eg. my Explorist 500 has a compass screen. When I use it as a compass, it is set to point to the true north pole, and from there I get the degrees/bearing I need to go. If someone said I need to walk 270 degrees MAG, I would set it to magnetic north.

 

This stuff ain't easy to learn over forums, but someone in the know who can sit down with you and your gear would have you getting it pretty quick.

[+climbingcrew]

Thanks for the help!

[+Minimike2]

East is Least and West is Beat.

Edited September 4, 2009 by Minimike2

[+The Jester]

East is Least and West is BeatBest.

Fixed it for you.

[+Prime Suspect]

East is Least and West is Beat.

 

Meet the Westles!