Three different compasses for map reading
Like many people I own a Silva Compass. Silva is a very well-known brand and makes a good range of compasses. I have a Silva Expedition 4, which is apparently modelled on a British Army compass, and offers all the compass features I think I have ever needed. (But maybe not. See below.)
The Silva Expedition 4 compass has:
- Bezel edge marked in degrees
- Millimetre and inch scales
- Stencil holes
- Silicone rubber feet for precision map work
- Sapphire jewel bearing for friction-free movement of the compass needle
- Romer scales: 1:25.000, 1:40.000 and 1:50.000
- Night-enabling luminous markings.
Mainly I have used the compass dial and needle, the red orienting lines to match up with the north direction on the map and the arrow pointer. Occasionally, I have also made use of the distance measurer and the magnifier.
I have also used the Romer scales. These help you to measure distance and accurately work out your six-figure grid reference on different scales of maps.
I have never used the stencil holes or the night-enabling markings. I may well have made use of the rubber feet but unknowingly.
What I really like about the Silva compass is that it is very simple to read the map through the clear compass face. It is simple to line up the red orienting lines on the compass with the north grid lines on the map.
The Silva compass also holds a steady bearing and it is very hard wearing. I have had mine stuffed in a rucksack for years and it is well used. It still looks almost new.
The Silva Expedition 4 compass is a recommended item of kit for the Duke of Edinburgh award. It sells for between £22 and £27.
Two new compasses
I have been sent a couple of other map-reading compasses to try.
Brunton TruArc 10
The Brunton TruArc 10 is a baseplate compass similar to the Silva Expedition 4. It feels very durable, just like the Silva compass, and includes all the measurement rulers you would expect, such as inches, centimetres and Romer scales, 1:25.000 and 1:50.000. There are lots of other extra Romer scale measurements but I have only ever used 1:25k and 1:50k so I am not sure how many you really need.
This compass has numerous extra Romer scales, including 1:24k, 1:62.5k, 1:63.36k and 1:250 k UTM.
To be honest, I find all the different scales in this one small Brunton gadget to be more confusing than helpful.
The one scale that is really good is the white inches and centimetres ruler along the edge. This can be flipped over to suit so you can have metric or imperial facing upwards.
The compass needle and degree markings are great. There’s an “Ever-North Magnet” so that regardless of potential interference from watches, GPS gadgets or strange rocks, the needle will give a true reading. The needle holds very steady when you are attempting to follow a bearing, even in very windy conditions.
This compass also comes with “GPS confidence circles” for various different map sizes and “errors”. This is how the holes work. (It’s what I have read on the internet although I am still not quite sure I understand it!)
Think of yourself standing at a cache. When you are there your GPS will say “You are xxft from where that cache is”.
If you drew a circle around where the GPS said zero was at and made the circle the size of the GPS error it should include that cache, which was the point of interest, plus more ground around it.
It’s another way to say, “You are within this area”. Using the circle you can see that area on a map.
This compass does not have a map magnifier. I also do not find it so easy to use to take a bearing on a map. The compass dial itself is not clear all the way through so I find it more difficult to line up the orienting lines with the grid on the map.
This compass does have a lot more degree markings around the circumference of the dial housing though, which I like.
It’s a sturdy compass and one that I think will withstand a lot of use and abuse. But I would prefer less in the way of features. Maybe I am just a simplistic map reader.
This summer, Brunton have donated 250 Tru Arc 3 compasses to The Scouts Association.
It sells for about £28 to £30.
Silva Race Jet Compass
The compass has see-through visibility for easy use with the map but no rulers, measurements or degrees.
There is no needle wobble and the rubber friction feet hold it still on top f a map, especially a map with a plastic cover.
It’s a simple gadget and very good at doing a specific job for orienteering. It does seem a bit pricey at £60. See The Orienteering Shop.
Tell me about your favourite compass.