Using a compass
Symbols & grid references.
11
Give a 4-figure grid reference for this grid
square.
Look familiar?
52 09
10
09
08
50
07
51
52
53
& grid
How manySymbols
symbols can
you references.
spot in this grid square?
52
Building
Field
boundary
Chapel
Spoil heap
Water
Train station
Minor road
Post office
Woodland
09
09
52
Pub!
River
Railway line
Using a compass.
What are the
basic points of a
compass?
How do you use a
compass to take a
bearing?
Using a map and a compass together effectively can mean
you can navigate very accurately. On an expedition, do
you want to walk any further than is absolutely necessary
with a heavy rucksack on your back?
If you do make a mistake and wander off your planned
route, you must retrace your steps until you reach the
point where you last knew where you were on the map.
Could you name all eight main points of a
compass?
orth
North West
North East
West
East
South West
South East
South
Direction
You should know from the last session that there are potentially
sixteen points of a compass you could use when describing direction.
North
West
East
South
OS maps are always drawn to be in line with the points of a compass.
Direction
N
W
S
E
Remember this when you are ‘setting the map / orientating it’ when
you are using it to navigate. This diagram shows how you can set the
map using visible features, i.e. things you can identify on the
landscape.
OS maps are always drawn to be in line with the points of a compass.
Direction
True North
This is what the
Earth spins around,
we do not use this.
Magnetic North
This is where the
compass
needle
points.
UK Grid North
This is close to True
North and is the
North we use on
maps.
There are actually three ‘North's’
commonly in use in Great Britain.
Magnetic north changes, currently the magnetic variation is 2° West
of UK Grid North.
The actual compass
Direction
Compasses have been used for centuries to aid navigation due to the fact that
the needle always points towards Magnetic North.
The compass you will use is an Ranger made by Silva. Remember, as
with all equipment loaned to you by D of E, look after them – these
cost around £25 each!
The actual compass
Direction
Don’t forget the other ways in which the compass can be useful to you:
• The magnifying lens will help you identify small features on the map
more easily.
• The scale along the edge of the base plate can help you measure
distances on the map.
How to take a bearing.
Taking a bearing can be invaluable when navigating, especially in poor
visibility or when you are not 100% which direction you should head in.
At Bronze Level, you shouldn’t really need to have to use a compass but
if you can then it may avoid you getting lost on an expedition when you
will be walking as a group, without a member of staff.
Taking a bearing will probably come in most useful just to double check
your route.
You’ll have an opportunity to practice taking a bearing on the Rivington
Day Walk.
How to take a bearing.
Step 1
Do make sure that the map is pointing
to the UK grid north – don’t have it set
/ orientated.
Put the edge of the compass along the
route you intend to travel along – here
it’s A - B.
Do make sure that the map and
compass are as horizontal as possible
when you do all of this.
How to take a bearing.
Step 2
With your map flat, next, turn the
compass
housing
so
that
the
orientating lines (red ones here) are in
line with the vertical eastings – the
vertical grid lines, on the map.
How to take a bearing.
Step 3
You should now add two degrees on in
order to take magnetic variation into
account.
The number you now should be able to
read at this point on the compass is
your bearing. On this diagram it is 50o.
How to take a bearing.
Step 4
Now take the compass off the map,
keeping it horizontal.
Now ‘put red to bed’’. Turn the whole
compass until the floating red needle
sits over the red north arrow on the
compass housing.
Now
keeping
these
two
together, follow the direction
of travel arrow.
Remember, once the compass
is set, you follow the
direction of travel arrow.
Do not follow the floating
red ‘north arrow’.
This is a common mistake
made by students.
If you do this, you will only
be travelling north.
Using a compass and taking a bearing is difficult when doing it for
the first time and requires practice – you will get this on the next
day walk.
Don’t worry if you don’t feel confident at this point, when you do ‘it
for real’ on the next day walk you’ll find it much easier.
Remember, you can revisit any of these power-point
resources by going onto the DofE area on the school
website.
Find the Bronze D of E folder then pick which of the
training sessions you would like to look at again.
It would be wise to look at this again before any
expedition – you WILL have to use a compass.