Declination Diagrams on a Topographic Map

[@STOKERMATIC]

Thanks for watching friends! Make sure you hit the like button and subscribe to stay up to date on future content. You can find gear on my Amazon Influencer Page Check out this page from www.amazon.com/shop/stokermatic

[@winstonalpha1286]

Brother.....for the record, i have been watching a boat load of videos from every where and every one teaching this stuff...its been a few years now and out of all the people teaching it here on youtube, you and your videos are the best ive seen....hands down....ive been binge watching your channel for the last week... You got a subscriber and a 1000 thumbs up brother....keep up the good work....from a neighbour up north ( Canada )

[@ppspsd]

Playing catch up on your map videos! It's a awesome refresher course, just like riding a bike. Thanks for posting! OUTSTANDING!!

[@caseykelso1]

This is second time ⌚'ing these videos 🎉

[@P6009D]

Let's assume my map's GN points to 12 o'clock. TN = Meridian points to 11 o'clock. MN = Compass needle points to 10 o'clock. Magnetic declination is the angle between 10 and 11. I have an adjustable compass and correct the declination + the difference between 11 and 12 which is the difference between TN and GN. In which situations should the difference between TN and GN be taken into account? I agree with you civilian maps are bad at informing about what and how things should be adjusted.

[@STOKERMATIC]

Wow, Thanks brother! Magnetic Declination would be the difference between 12 and 10 (GN and MN). TN means nothing when using map and compass (assuming as in your scenario that TN isn't the same as GN). To use a grid azimuth with a compass, or to use a magnetic azimuth with a map, the math you must account for is the difference between magnetic north and grid north. Hope that helps! When to account: always if 5 degrees or more. Especially if moving more than 400 meters. If it's 4 degrees or less, it's always good practice to account for it (but it won't make that much of a difference if traveling short distances). If you have a compass where you can preset it, there's no reason not to.

[@P6009D]

@@STOKERMATIC Yes, you should probably avoid unnecessary mathematics when you are tired in the forest. I have seen some adjust between MN and TN, then turn the shed in the compass parallel to the meridian lines on the map that are exposed on Swedish maps. I have two tools, a map (GN) and a compass (MN), where Santa lives is irrelevant. Thanks for the reply.

[@martinkolar3595]

A true service service. Thanks!

[@zrig1]

When working with maps, understanding magnetic declination is crucial for accurate navigation. It’s not as simple as using the declination shown on your map if it’s older than a year or two. Here’s why and how to adjust for this: Good maps typically include a date indicating when the declination was calculated and an annual drift value showing how much the declination changes per year (either east or west). This allows you to calculate the "delta," or change in declination, to keep your navigation accurate even with an older map. How to Calculate Declination for Your Map: Find the Map’s Date and Declination: Look for the printed declination value and the date it was recorded on your map. Note whether the annual drift is east or west. Determine the Age of the Map: Subtract the map’s date from the current year to find how many years have passed. Calculate the Total Drift: Multiply the annual drift value by the number of years since the map’s date. Example: If the annual drift is 0.2° west and the map is 10 years old, the total drift is 0.2°×10=2° Adjust the Declination: Add or subtract the total drift to the declination shown on your map, depending on whether the drift is east (add) or west (subtract). Example: If the original declination was 5° east, and the total drift is 2° west, the updated declination is 5°−2°=3°east. By following these steps, you can confidently navigate with an older map and account for changes in the Earth’s magnetic field over time. Accurate declination ensures your compass readings align with your map for reliable navigation!

[@philippejoyal8065]

Thanks a lot! The way you explained it really simplified my understanding and I am now more confident of my plotted azimuts.

[@mawgateway]

Stoker, at 6:15 you say that if you're to the west of the isogonic line, you need to add to convert from grid to magnetic. That's backward. Being physically west of isogonic and converting from grid to mag requires subtracting from grid. Converting from mag to grid requires adding to mag. Maybe you were referring to the direction of the compass declination rather than your physical location (east or west of the isogonic line). This stuff seems like it should be simple, but it's easy to confuse it. Left, right, add, subtract, magnetic, grid. Wait a minute, let me think this through again.

[@STOKERMATIC]

LARS.

[@mawgateway]

@@STOKERMATIC The LARS acronym is useful. But here's the confusion in what you're saying starting at 6:15. You said if you are west (or left) of the isogonic line, then you add. But the LARS thing doesn't base left or right on your personal position compared to the isogonic line. The left/right applies to the direction of your declination. If I am west (or left) of the line, my declination is to the right. Therefore, right declination = subtract in order to convert from map to compass. By the way, you're my favorite source of instruction on land navigation. Please keep it up. Great stuff.

[@pennfitness]

I really appreciate your videos, I pinned SGT and did my first comp successfully and your videos helped🙌

[@STOKERMATIC]

🇺🇸👊

[@johnstevenson9429]

I was once given this saying to adjust for declination. Always assuming you are begining with a grid bearing: west is best and east is least. If the declination diagram on the map shows mag is west of grid then add. If it shows it east of grid then subtract. This only works if your going from grid to magnetic.

[@jacobriley7970]

From the video: "If you're to the left - to the west of the isogonic line, then your left-add/right-subtract is going to be--if your trying to convert from grid to magnetic--you're going to Add (left add), but if you're on the east side of the isogonic line, if you're on the right coast as opposed to the left coast, then it's going to be the exact opposite." Isn't this the exact opposite of what you're saying, John Stevenson? Because the west side of the U.S. shows "mag is east of grid" on declination diagrams, and the east side of the U.S. shows "mag is west of grid" on declination diagrams. Meaning if you're on the west side, you would subtract (grid to magnetic). Stoker says ADDif you're on the west coast, though, as per above quote. Every time I think I have it figured out, I feel like I hear something that contradicts what I thought might be true. lol.

[@johnstevenson9429]

@@jacobriley7970 yes I know what you mean. That was only what I was told. I guess someone will figure it out

[@jacobriley7970]

@@johnstevenson9429 It totally seems like what you said is correct though. That's what's throwing me off. I think, maybe, stoker misspoke?

[@johnstevenson9429]

@@jacobriley7970 I don't know Jacob. If the choice is between me and what I read on the internet and Stoker, I would go with Stoker...lol

[@jacobriley7970]

Yeah, but what you said matches up to what someone told me IRL that's good at Land Nav, so... hahaha. What a pickle, could mean the difference between arriving at your destination, and being hundreds of kilometers away >.< But thanks for the interaction man, have a blessed day.

[@josephlascuola5751]

I have a question related to declination. If I adjust my compass for a westerly declination (I’m in an area that has an 11° W declination) and I’m in the field and shoot a bearing to an object located at 118°, would I subtract 11° from the 118° to find the object on the map using a bearing of 107°, or use the compass bearing of 118° since the compass is adjusted for declination? I think I will have a firm understanding of declination once I have a clarification on this scenario. I look forward to your reply. Thank you. Joe L.

[@STOKERMATIC]

To draw an azimuth on a map that will be relative to what you determined with your compass you would subtract the declination before taking pen to paper. Hope that helps.

[@STOKERMATIC]

...if your using a baseplate compass and you have it preset, there’s no need to make an additional adjustment. If your using a lensatic compass what you shoot is magnetic and you need to adjust.

[@diynhamy8452]

Very useful . Thank you SGT

[@STOKERMATIC]

Glad you enjoyed it!

[@Rickflairshair]

Thank Top. Glad you made this video. Its such a great learning tool

[@STOKERMATIC]

Right on amigo! I think I could have done a better job looking back, but hope it still helps out someone.

[@GryphonIndustrial]

Theres a bit with map declination I don't get. MGRS maps make sense because the grids are straight with the map but I have a local topo map and the grid lines don't run parallel to the map. They are canted. Do I still adjust my declination to grid north or for that map do I use true north and just kinda ignore the grid lines?

[@STOKERMATIC]

If you’d like you can send me a picture - [e-mail]. The GM angle is to help convert grid azimuths to magnetic. If the map has one you should be able to use it. If it doesn’t you couldn’t use your areas GM (when trying to convert grid to mag or mag to grid) because it’s going to be different. Hope that helps!

[@t_train3796]

Hurricane, you could use your compass and orient your grid lines to magnetic North. That way whatever you plot off of it has the declination factored in.

[@GryphonIndustrial]

@@STOKERMATIC I rewatched your land nav videos and I finally got it. Light bulb just wasn't going on before. I also just scored a 2005 cammenga compass for $25 at an auction so now I just gotta print me a topo and get out there in the dirt!

[@rayvila7761]

Ray Vila what if gn line falls between tn line and mn line, what then? thanks a lot...

[@STOKERMATIC]

Only thing that matters for declination is the difference/relationship between GN & MN: kzbin.info/www/bejne/hYCpe4pqptJlh9k

[@tomstclair3390]

Thank you

[@rwutube]

Good video. I have a suggestion for another video. I’m in my 40s, practicing physician, interested in joining the Army reserves. I’d like to hear your comments about how Army members view reservists, what the experience is like, opportunities that exist beyond just minimum commitment, etc. Thanks and keep up the good work!

[@STOKERMATIC]

Ron, I can work up a video response but will post in on my other channel kzbin.info/door/76WnGz_DkqzDc7f-KEjTLQ In short - if it’s a goal do it! As a young Marine I couldn’t grasp reserves. It wasn’t until I was in the Army serving with an active/reserve unit that I began to appreciate the reserves.

[@caseykelso1]

Hitting up old gold mines in Nevada , brushing up ... again 🎉 could just use my Garmin, but wheres the Fun in that🍻

[@donaldburton6869]

If I am using a map that was upgraded in 1981 and the declination is listed at 17 deg. But the declination is now 14.8 deg. What number do I use? I know it’s only 2.2 deg. different. Thanks! Oh yeah I love all your videos. VERY informational!

[@STOKERMATIC]

Use the recent declination. In your case, I’d use an even 15

[@dancurrey6073]

What would happen if you lined your compass up with Grid North on the map, then subtracted the GM angle (if westerly) to orient the map to Magnetic North. Couldn’t you then get your azimuth right off the map by aligning the two points with your compass (assuming you have a properly oriented map to Magnetic North).

[@STOKERMATIC]

Yes. If the map is aligned to MN - you could use the edge of your compass (connecting point to point) and read the azimuth on your compass which would give you a magnetic azimuth from point to point.

[@32FluidOz]

Stoker, I've seen your later videos where you explain the LARS method but I don't believe you mentioned "LARS" in this video. The LARS method of converting G-M or M-G works the same whether your current declination is East or West, correct?

[@STOKERMATIC]

It does. If your moving the angle to the LEFT - you always ADD (for example on left coast moving from Mag to Grid, on the right coast moving from grid to mag). Visa versa for moving angles to the right - subtract.

[@ronvonbargen8411]

Can you orientate your map to the declination angle?

[@STOKERMATIC]

You bet - and in fact, you should because that's the actual direction to the north pole. But if the declination isn't that much, it won't be a big deal. I'll try to work up up a demonstration of this in my area since my declination is fairly great.

[@ronvonbargen8411]

That would be great

[@JeffMeadowsOutdoors]

Being in the east, I just know my compass will read 8 degrees more than my map. ( 7 or 9 degrees if I drive more than about 40 minutes either way) Thanks Stoker for the videos!

[@STOKERMATIC]

Right on Jeff! I could have explained a little more about easterly and westerly declination but maybe next time.

[@Stone-Wolf-Outdoors]

great info Brother :)

[@STOKERMATIC]

Tony! I have a compass for ya! Will get it to you in the next few weeks. Also - looking for a spot - public land - little to no under growth, within an hour of Oly. Needs to be at least 1,000m square. Any ideas? Will be for an in person class.

[@Stone-Wolf-Outdoors]

@@STOKERMATIC there is a area by me that has what you are looking for nature preserve just may have to have orange if it during hunting season

[@rdaugherty52]

Stoker I am getting old and my brain forgets now so I have to keep referring to your videos to remember this stuff. Is it absolutely nessary for my well being nope. This is what I do. I take a map I make a tiny mark and call this my patrol base. I then make 7 or 8 tiny little marks usually in a circle back to my patrol base. One mark might be a ammo can another water, maybe a lurp patrol, a sniper, a observation point, and then back to the base. Now I will make up a mission I will pick up the ammo and water and take it to the lurps, I make it a little harder by having a set time to deliver. Then to the sniper, to the observation point and back to the patrol base right after dark. I plot the asmith to each point I know how many meters to each and how long it takes me to walk. This to me is fun. I may not be normal. Have you thought about a set of Stoker cards you can pull out to refresh your memory on some of this stuff? Oh well thanks Stoker see ya man.

[@STOKERMATIC]

Good training and idea!

[@rickm4295]

This map stuff is awesome. Id like to see you run a "mission" start to finish like your very 1st video but a revised version , HA.

[@STOKERMATIC]

Right on! I filmed a demo that I’m still working on - similar but longer. But I’m thinking of a series - short and long movements. I’m rambling...we’ll see what I can come up with. Lol

[@rickm4295]

@@STOKERMATIC That would be so great. I really like this particular topic. Its one of the most useful skills you can have in your head. Love it

[@ericdee6802]

How the heck did I miss this video???? Must be your new microphone 🎤🤯

[@STOKERMATIC]

I dunno Eric! lol

[@joefennell7535]

Top notch Top

[@STOKERMATIC]

We’re in the danger zone Joe!

[@colinrobert-kv2up]

Ha ha. As noticed after training,, learn careful, magnetic field interest, pointers appears,m. A pull to it. Them. , lead follow , groups, more a cross country at once. Sneaky like, at night. Control source code prmg form pictures of writing identity of,, more information on sight more information about status of spirit forms using rivers to travel in. From. Oceans. Pnt one. Two pnt rivers. Three. In land. Patterns. Keep safe. John.