How to calculate declination

The ability to calculate magnetic declination is a crucial skill for anyone venturing into the wilderness, especially for activities like hiking, camping, or navigating off the beaten path. Of course normally you can simply look on line but if you are in an area without internet access you will need to be able calculate the magnetic declination for the area with just the information on your map.

All the information required to calculate magnetic declination manually can be found on your map and, using some very simple maths, you will have a good idea of what the magnetic declination is for that area.

This skill adds a layer of preparedness and confidence for those exploring nature's less-travelled paths.

[TheMetalDetectingChannel]

Nice meeting you today on the hills pal!

[percyveer]

I have been watching you for a while now and you are without doubt my favourite YouTuber. I haven't understood one word you have said but I have thoroughly enjoyed it. Keep 'em coming 👏

[stpetie]

Thanks for the upload and for something new to think about. Always happy to see another of your videos.

[David-ifvi]

Here is a tip that will help you. At 2:55, you have the change at 12' = 12 minutes per year. X 5 years will give you 1* degree of change.
This will not cause much errors in your readings.
Take your map, and a long ruler. Using the magnetic bearing indicator/direction. Mark the entire map with ruled pencil lines.
You now have your magnetic lines, and you work directly from these.
What also is as important is navigating using the contour lines.

[moorejl]

If you are at a known location on the map, measure and log the grid north bearing to a feature on the map. Then take a magnetic bearing to that same feature with your compass and log. The difference is your declination. No need to make an estimated calculation based on the year the map was printed.

[chucktaylor]

If one were to calculate a bearing from two known points on a topographic map and compare that number with the bearing of the same two points read on a compass set to zero declination, would it be safe to assume that the magnetic declination is simply the difference between the two bearings?

[darkporpoise]

It can be worth periodically "refreshing" the declination info on your old maps to keep them up to date. Only takes a couple of minutes and a sharpie.

[JackAlford]

Legend mate, thanks for this. Great video again 👏🏼

[arthurvandelay]

G’day from Australia. I’ve relatively recently found your channel and loving it. I’m wondering what you know about the flipping of the magnetic poles, the chance of it happening any time soon, and what effect it will have, both to navigation in the short term and also to life in general longer term.

[IrelandOutdoors]

Hi Wayne, great video, but would you be able to do one on measuring the actual declination out in the field and not estimating. Think that would be a good one!

[zembalu]

Can there be local abnormalities in the magnetic field? Of course, there are manmade ones, like power lines or bridges of steel, but I think of geologic formations and the like. If that is so, in which magnitude? I think, with a compass reading going wrong even by a degree would not really matter. But I use a monocular telescope (8x30) with built in compass and streak plate. Mainly for better eyesight, but the compass comes in handy for triangulation, which is a nice hobby :-).

[stuartadair]

Does that website give you declination or GMA?

[mrparlanejxtra]

I have just had a brilliant idea. If you take your compass neck string and a spirit based marker pen you can colour in every second centremetre to make a measuring tape so you can lay that on your track on the map to measure out the distance you are going to travel.

[lifeontherocks]

Great video.
Is there a good phone app for telling you your declination?

[davemc]

What? No waffle? Or was it all waffling?

[mrparlanejxtra]

You do realise that if you ask the computer what the co-ordinates for the house in Pencil-vania st. are, it will tell them who is looking it up?

[davidbelding]

How confusing that the terms declination and variation are synonyms in America but also have quite different meanings depending on whether they are used in nautical navigation, land navigation or astronomy. As a mariner variation is the difference between true and magnetic bearings and declination is an angular measurement from the celestial equator used in celestial navigation. 🤪

[denisripley]

Hang on ! For a moment there I was thinking about Magnetic Inclunition.. which really is a black art.

[billy]

So. ..Check your declination, before your peregrination. 🤔🙄💪

[davehumpleby]

I've been subscribed to your channel for a while now, but expect an influx of viewers from Paul Messner's channel.
If you watch his latest post, you'll understand. 😂