Thread: Navigation with compass and map

Originally Posted by Shooter

If you fancy a trip to the Central North island then I could take you out for a day or two, show you the ropes and put you through your paces? I'm not saying that you cant learn from books or the internet but there is nothing like a bit of one on one instruction! As its all the little bits if information that may be missed or incorrectly interpreted when learning on your own. Plenty of hunting around these parts too...

Can I come too? I need to uh....practice navigation....

Originally Posted by stug

Mountain Safety doesn't run courses anymore, they sacked all their instructors.

The firearms license safety course only or all courses @stug ?

Originally Posted by ebf

The firearms license safety course only or all courses @stug ?

Firearms safety course is still happening, it was the firearms people and the technical committee they let go. All the other instructors and courses are now gone. Head office felt they weren't reaching enough people. So one of their ideas is to get people to stand at track ends and hand out pamphlets, I kid you not!
They will end up being like Water Safety NZ, someone to go to for a sound bite, but not actively involved in teaching people.

some notes for you @Myk...

Basics
Compass points at Magnetic
Bearing: a horizontal angle measured clockwise from north
Compass bearing + deviation = magnetic bearing
Magnetic bearing + variation = true bearing.
True Virgins Make Dull Companions, Add Whiskey (T, V, M, D, C, A, W)
True, Variation, Magnetic, Deviation, Compass, Add Westerly

Compass
Direction of travel arrow: on base plate
Orienting arrow: red arrow on base of dial
Orienting lines: parallel lines on base of dial

Orienting map with compass
Turn dial so that N is lined up with direction of travel arrow
Compass on map, long edge parallel to map N/S lines, dial N to map N
Turn map for mag. var.

Obtaining grid bearing from terrain
Direction of travel arrow at feature
Turn dial for mag. var.
Read bearing
Follow bearing, ensure mag. needle points to mag. var.

Obtaining grid bearing from map
Find pos on map
Compass on map, long edge toward destination
Direction of travel arrow at destination
Turn dial orienting lines parallel, dial N to map N
Read bearing
Turn yourself for mag. var.
Direction of travel arrow points at destination
Ensure mag. needle points to mag. var.

Identifying feature using grid bearing (known pos.)
Direction of travel arrow at feature
Turn dial so needle at mag. var.
Compass on map, long edge on pos., direction of travel arrow at feature
Turn base plate until orienting lines parallel (edge still on pos)
Feature will lie along long edge

Obtaining position by triangulation
Identify feature and take grid bearing (B)
Plot bearing on map. Turn base plate until orienting lines parallel (edge still on feature)
Position lies along the line
If not on known ridge, river etc, take second bearing (pref 90 deg.)
Three bearings: pos within triangle

Travel on a bearing
Compass horizontal, direction of travel arrow ahead
Turn yourself for mag. var.
Adjust direction so mag. needle keeps pointing at mag. var.

Back bearing
Differs 180 deg. from bearing you are using
Leave compass set on bearing
Turn yourself 180 deg, white end of needle pointing at mag. var.

Detour around obstacle (back bearing)
Leave compass set on bearing
Locate marker where course meets obstacle
Travel around obstacle
Take back bearing, do not adjust compass
If directly opposite marker, back on line of travel
Turn around till compass needle re-set on original bearing

Detour around obstacle (right angle)
Leave compass set on bearing
Turn L or R 90 deg, pace out distance
Turn back on original bearing, pace distance
Turn toward original line of travel (90 deg), pace distance
Turn back onto original bearing and continue

and a couple of last ones

Deviation is specific to each compass.
Variation is specific to where you are on earth.

An easy way to remember whether to add or subtract variation other than the "true virgins" mnemonic is this:
If you put your compass onto the map - you add variation.
If you take your compass off the map - you subtract variation.

Originally Posted by ebf

If you put your compass onto the map - you add variation.
If you take your compass off the map - you subtract variation.

Mag - Grid - Add (Machine Gun Anne)
Grid - Mag - Subtract (Grand Ma Sucks)

The best skill to have is to be able to locate yourself on the map, without a compass. It is not often that you can actually see three points far enough away to be able to triangulate your position.
Learn to look at a map and recognise ridges, streams etc. Keep looking at the map and mark off features as you meet them. It can be difficult as what looks a big stream on the ground might not be marked on a map etc. Also try and judge distance you have travelled as well. Start with a marked track and mark off the features as you go.

How do you Kaimai guys go navigating in the thick stuff. Ive tried it with a compass and map but fail miserably due to not being able to see more then 30m at time. I can head in the direction of a track no problems but putting my finger on a point on the map and saying im there isn't working.

Originally Posted by stug

Learn to look at a map and recognise ridges, streams etc. Keep looking at the map and mark off features as you meet them. It can be difficult as what looks a big stream on the ground might not be marked on a map etc. Also try and judge distance you have travelled as well. Start with a marked track and mark off the features as you go.

Yep, useful skill to have. If the features you're finding on the ground aren't the ones you expect from where you think you are on the map, stop and look at the map more closely - you probably haven't covered as much ground as you thought (or sometimes you've gone further, but more often the terrain has slowed you more than you realise). Sometimes you won't know exactly until you reach a more obvious landmark, but don't just assume you are where you intended if the evidence seems to suggest otherwise.

Had to laugh watching the map of GPS trackers during the godzone adventure race earlier this year - 3 or 4 teams got confused in the dark and spent hours going up the wrong valley, a couple of them realised and turned back but the others kept going the wrong way for half the next day as well. Eventually they sent a chopper up to find them, apparently it was a funny conversation: "do you know where you are?" ... "no idea" ... "where's your map, I'll show you" ... "umm... in my pack I think". Maps don't do much if you don't look at them!

As Tussock says its flat, relatively featureless ground thats the trickiest, and maps never show everything.

Originally Posted by Rusky

How do you Kaimai guys go navigating in the thick stuff. Ive tried it with a compass and map but fail miserably due to not being able to see more then 30m at time. I can head in the direction of a track no problems but putting my finger on a point on the map and saying im there isn't working.

I do lots of circles mate Sit, scratch head, and do a bigger circle My compass, map and GPS gets me close enough to get where I'm going.

I learnt to use map & compass when I joined the local hunting club (Levin)...im surprised the deer stalkers don't do this ?

Originally Posted by ebf

@Myk, practise makes perfect....

Take a map and compass when you go for short walks. Take bearings off known landmarks, triangulate your position. Try to identify your position by identifying terrain features on the map against what your see in real life..

Self taught lessons like this will always be the best learnt and remembered... nothing beats actual experience...
1)Get a reasonable compass not big and heavy because you need to carry it.
2) Understand how magnetic fields from steel.. like your rifle will affect compass headings... so you do not fall into that trap
3) Understand declination or variation... the difference between True and Magnetic north... NZ varies between 18 and 25 degrees.
4) Go play in an area you are familiar with... you will soon pick up the skills.

Early in my bush whacking days I got fogged in on the Kelly range tops... walked round in circles and got lost.... ever since I have always carried a compass and have had many occasions when I have really needed it to get out of trouble.

Originally Posted by Daggers_187

Can I come too? I need to uh....practice navigation....

My offer is to anyone! If you are looking for some hands on experience then drop me a PM. I am busy for the next three weeks but am pretty open after that.

Like others have said practice makes perfect.

Originally Posted by Tussock

I will make the same offer. Turn up on the Waitaki River bed at X date at Y location and I will run a compass course. Don't care when or what you bring.

Anyone who can find Z people PM me.

I promise to stop writing like I'm forming an irritating equation. Some days I am switching between here and talking to chemical engineers and it fucks with your head.

The only thing that someone needs to bring to you at location Z on the Xth at location Y... is your meds.

The engineers will want the compass bearing to 4 decimal places.