Base Plate Compass, "every" part identified and explained

Published 2023-04-17
Here is a list of EVERY part and function on a standard Base Plate Compass.

I did an internet search this morning and there wasn’t one single website or video showing “every” part on a Base Plate Compass so I thought it would be interesting to make a video, so at least the information is out there.

This is a long video so if you want to fast-forward to a particular feature, here is the order they are described. You can "click" the time to jump to that point in the video.

1. Direction arrow 3:20
2. Luminous pointer 3:50
3. Romer scales 4:15
4. Bezel/dial 5:35
5. Orienting lines 6:09
6. Ruler (imperial) 7:08
7. Magnetic needle 7:30
8. Risers 8:15
9. Lanyard attachment 8:50
10. Orienting arrow 9:15
11. Ruler (metric) 10:00
12. Declination scales 10:15
13. Index Mark / Line 11:35
14. Hole with crosshairs 12:10
15. Parallax Line(s) 12:50
16. Magnifier 14:10
17. Label holder 14:35
18. Sighting hole 17:20
19. Sighting mirror 18:10
20. Sighting Lines (H) 19:25
21. Sighting Lines (V) 19:40
22. Index Line 20:45


Here are the links mentioned in the video:
Take UTM coordinates /Grid reference with compass    • UTM coordinates & grid references wit...  
A simple method of dealing with magnetic declination    • Magnetic Declination (very) simplified  
Slope angle with and without an inclinometer    • Slope angle with or without a clinometer  

All Comments (21)
  • @richardmeyer83
    You left out the most important part of reading a mirror compass, if you look at the compass and then look back up at the mirror you will see a picture of a guy that’s lost
  • @kwgm8578
    I learned to use a base compass in scouts -- about 60 years ago. Thanks for the refresher!
  • @MrProphetius
    never thought of buying a compass, never needed one. after watching this, i bought one.
  • @allenmorgan
    I love it when something unexpected pops up in my feed that gives me so much enjoyment. Bit of a hunt to find my old Silva to follow along but as a bonus came across my slide rule too. I hope kids and grandkids will humour me.
  • @impromptu24
    I've never in my 40 years held a compass in hand, but this is the YouTube video I never knew I needed to watch! Great stuff!
  • When I was sixteen I'll never forget doing my Bonze Duke of Edinburgh Award in the Pennines, the fog came down whilst we were up a rather large hill on a peaty feature less landscape. Using a map & compass I managed to navigate my group down to the next checkpoint which was a phone box. It wasn't made easy when half of the group wanted to go back and I had a doubt whether they had really grasped the art of orienteering. It was one of those situations were despite explaining everything clearly they still weren't getting it, as I had the map & compass I stopped trying to negotiate and carried on and the group followed.
  • @YTusercomment
    Fantastic instructional videos...thank you. I NEVER venture into the forest depending solely on a battery-operated GPS unit or smartphone GPS. I always carry my Garmin GPS, a baseplate compass, and printed maps.
  • @Man_Cave
    I kept one of these on my person at all times when serving in the U.S. Marines from 1981-1985. I still have it to this day. It did everything I required for map and field navigation.
  • @ianbelletti6241
    One thing to be aware of is that not all maps are oriented to match North to being straight up from top dead center. Always check the map's compass rose to be certain of the exact North orientation on the map.
  • @nikob5899
    This is brilliant. I've always wondered what the small circular thing was. I contacted Silva customer services, and they didn't even know. You are right. It's not shown anywhere on a website. But now I know, thanks!
  • @KarlHeckman
    Bravo. Well done sir. I'm a map and compass nerd. It's nice to have you here.
  • @timothyhowes2942
    Excellent, simple, clear and concise. Thank you for sharing your knowledge.
  • @gregryan3252
    Learning how to read and use a compass is one of those skills you never knew you needed until the battery in your GPS goes dead and you freak out because you just realized how lost you really are. Thank God I learned these analog skills when I was in the army.
  • @LockBits-ts6eo
    I'm a bit miffed, that I hadn't found you before now! Thanks very much, you're great to watch. I'm also jealous of your collection of compasses.
  • No longer a compass virgin: I watched straight thru. [New Subscriber!] Plainly, THIS is a video I will need to watch a few times. I've done what I thought was a fair amount of BASIC map reading, driving about the USA, but just orienting myself very generally to the compass points from a general awareness of directions about me... principally, the directions of sunrise/sunset. (As long as you make no excursions from the roadway, this seems to work...) But Your video is my FIRST introduction to glimpsing the technical basics of cartography - a subject to which some have devoted their careers. I am humbled by your encyclopedic grasp of the business! Um...Moss still grows on the Northern aspect of trees in the forests, yes? Over the past decade, I've been following the reports on the drifting positions of our planet's magnetic poles from their long-stable positions. When I've mentioned this to some people, they scoff and look at me as if I were a madman. They stop to ponder a little when I mention that a number of international airports have had to redesignate the compass heading identifications for their runways, because of the meandering of the magnetic poles.
  • @farside51
    Great refresher video for me. I was a scout leader many years ago and was in charge of teaching young scouts orienteering and maps out in wooded trails. So much more fun and interesting for them to lean the skill without use of electronics. No batteries required.😂
  • @DoctorMangler
    Thank you so much for posting this, I've used compasses and hand transits for a long time and I learned a lot!
  • @mikeyb4610
    Wow all that in one small piece of plastic & numbers!….thanks for sharing I’ve learned so much from this 🗺️🙌✨
  • @BothanboatsIdler
    This video makes me want a new compass... You deserve a bit of Silva sponsorship for this mate! 😆 superb stuff, thank you!