Setting Up My Gps

[Big_Dave]

I've been active in hte hunt for some time but I always wonder if my GPS is set up correctly. For example, is it important to use magnetic north or true north od does it make a difference? I have options for which NEMA set up I use. Is one better than the other and why? Can you help me out?

Thanks Big Dave

[+Moose Mob]

As far as whether the GPS is setup to magnetic or true, it really doesn't matter for the vast majority of the hunts. The arrow will still point you in a direction that will most likely be the worst approach, and the coordinates will still be the same.

 

There are some offset (multi) caches that will tell you to go bearing 075 M for 150 ft, in which case that cache should tell you if it's Magnetic or True. If you know the local declination, then you can do the math on the fly.

 

I am going to make the assumption that most everyone is setup for the factory default.

 

Welcome to the obsession!

[+MDAgent]

Ok, so my question was about True North - so I did a search to see if the topic was already covered - good, huh?

 

However, I'm not sure this answers my question. What is the difference between True North and Magnetic North?

 

I think my eXplorist 500 was factory defaulted to Magnetic North.

[+Miragee]

Here is an article about compasses, true north, magnetic north, and all that stuff:

 

Compass deviations and variations

[+MDAgent]

Thank you so much!!! The article is very interesting... if not head-scratching. I'm not sure if it answers which one is more accurate when it comes to GPS, but it seems that it's important that the coordinates given use the same pole as the GPS setting. At least, that is how it seems from the story about the boat being off course.

 

I will study it more and see if I can develop a deeper understanding.

[+Miragee]

I don't think it is important in relation to Geocaching, unless someone adds a puzzle aspect to the cache listing relating to True or Magnetic north.

 

However, if you are in the intercoastal waterway and are trying to navigate with a compass and navigation charts, it is VERY important to figure all those things out correctly.

 

I still remember the Mnemonic saying for remembering one of the calculations, and I took those Coastwise Navigation classes thirty years ago.

 

T -- True North

V -- Variation

M -- Magnetic

D -- Deviation

C -- Compass heading

 

It was True Virgins Make Dull Company

[+Sputnik 57]

True vs. Mag makes absolutely no difference to you when caching with your GPSr. The only time it might matter is if you are using a paper map. If the map shows the ridge with the cache is due north, you need to know if the map is oriented to true north or magnetic north.

 

Cache on happily ignoring true vs. magnetic unless you need to are using a paper map, or unless a multi-cache tells you to to "take a bearing" from your current location.

[+MDAgent]

Thank you - WOW!

Everyone on this Web site is so helpful. Now I know what to watch for when doing a puzzle cache that includes bearings.

[Geocachaholic]

You're welcome . . .

 

It is a nice group.