Navigation

[FerlasDave]

I have just noticed there are not many threads on navigation on here, which is strange i think as nav is a big skill for the outdoors. Just wondering what the reason was for this or have I missed a thread?

Reason I'm asking is 'Im currently putting together a small nav manual for some of my DofE students who are struggling a bit. Has anyone already done this or would people be interested in a 'nav guide' thread?

 

[Toddy]

Good idea

There have been threads, on everything from stars to compasses and watches, but it's a timely issue and it'd be good to see it come up afresh

cheers,
Toddy

 

[Barn Owl]

Great idea Davey, i badly need a refresher course actually in the field.

I would also ask you to explain how to set up a compass that has the declination compensator on it.

 

[yeha]

I bought the Ultimate Navigation Manual by Lyle Brotherton. He has a website and forum here.

 

[mrcharly]

Excellent idea.

Don't want to seem to be teaching you to suck eggs, but do please make sure your manual emphasises using linear features and aiming off.

I've helped with DoE and these concepts don't seem to be taught to the children. They get really bewildered when walking on a bearing and missing their target.

 

[Dunx]

Sounds like a good idea. Know a bit of the theory, but not actually put it into practice yet.

 

[mrcharly]

Maybe I should add that my background in this is primarily in orienteering. I was heavily into competing up to a state level when I was a teenager.

 

[Chris the Cat]

I rubbish, so its a yes from me!

da C.

 

[ged]

It's a big subject which needs a lot of thought and work. I have an entire shelf devoted just to books on marine navigation (one of them is about using and adjusting the magnetic compass) and there are still one or two I'll add if I ever think I'll find the time to read them.

Forum threads tend to be a bit superficial and they very often meander all over the place, so I wonder if it's the best way to cover the topic.

Having said that there are links to articles here and there on the site and I'd think a carefully structured article containing a bunch of well-chosen pointers to resources could be very useful.

If you're thinking of the "BCUK Navigation Manual" then good luck with the project and I'll look in every year or so to see how it's coming along!

 

[dump of the stig]

Great idea Davey, i badly need a refresher course actually in the field.

I would also ask you to explain how to set up a compass that has the declination compensator on it. QUOTE]

EDIT, I did give you an answer to this, but then I confussed my self unexpectedly so yeah I need a refresher too

 

[ged]

... jumping in a bit here ...

I don't think that's quite what Barn Owl had in mind. The Earth's magnetic field does not generally act in a horizontal plane at any particular place. This can cause an error in a magnetic compass which changes with location. The effect is similar to 'heeling error' in a yacht.

Many magnetic compasses are calibrated for a particular area, some can be adjusted to compensate.

Random link dfrom the Web:

http://www.rescuedynamics.ca/articles/MagDecFAQ.htm

 

[Dunx]

You mean the difference between magnetic and true north?

 

[copper_head]

You mean the difference between magnetic and true north?

It would be the difference between magnetic and grid north.

 

[rg598]

This was mostly written for the US, but it may be of some use: Magnetic Declination, and How to Calculate it Using the Sun: http://woodtrekker.blogspot.com/2012/10/using-sun-to-find-magnetic-declination.html

 

[FerlasDave]

A lot of replies there guys thanks. So it seems a little thread including some of the main points may be a good idea then.. If you bear with me as I have limited access to the Internet at the moment and ill start working on it hopefully next week. Not planning anything of a grand scale like a 'BCUK Navigation Manual' but ill see how it goes.

As for teaching linear features etc our group are only bronze at the moment and usually leave in depth navigation for silver awards but I think your right, there's more to reading a map than just taking a bearing...

 

[santaman2000]

It would be the difference between magnetic and grid north.

No he got it right. Declination is the difference between magnetic and true north. Grid north is still a third component.

 

[santaman2000]

This was mostly written for the US, but it may be of some use: Magnetic Declination, and How to Calculate it Using the Sun: http://woodtrekker.blogspot.com/2012/10/using-sun-to-find-magnetic-declination.html

It should work just as well anywhere north of the equator.

 

[FerlasDave]

Well, this is turning out to be a lot bigger than I expected. I didnt realise there were so many 'basic' skills when it came to nav.

Heres a snippet;

''Grids

Grid lines are similar to lines of latitude and longitude, however due to the earth’s curvature these lines are slightly different.
The lines running horizontally across the map are called northings (as they move northward in parallels) and the lines running vertically across the map are called eastings (as they move eastward in parallels.) Together where these lines intersect they create grid squares. On a 1.25,000 scale map each grid square will be 4cm across and will represent 1 kilometre on the ground.''