Discussion: Sights for a Baseplate Compass

So here is an idea - I usually use a baseplate compass (sorry...never got used to a thumb compass, let's not have a discussion around that please). After taking a bearing on the map, the next step would be to aim at a distant object (e.g. a powerline pole). I was thinking about installing a rear and front sights, similar to a gun, so that I could look through and focus on an object. I'm talking about something super basic, made of plastic that wouldn't take much space. This might sound like a clumsy way of aiming, might take a few seconds to use during a race but it is still a good compromise rather than using a sighting compass (those with a mirror that blinds me all the time) or use a bulky field navigation compass.

Pros and cons anyone? design ideas? alternatives?

This is what it may look like looking through the sights...took it from an M16 sights illustration :-)

https://i.ibb.co/Y0YFxRh/Sight.jpg

So how do you know what the needle is doing when you look through the sights?

To say nothing about trying to read the map at the same time.

Orienteering's taken a strange turn when you're using straight line bearings and telescopic sights to navigate the course. Just use the map!

using straight line bearings and telescopic sights to navigate the course

That's called rogaining

Combining orienteering with gun owning would probably be smart marketing move in the US.

Maybe use a sighting compass? Silva have them.

The use of a compass in orienteering in overrated.

Are we being pranked here by Mr No ID?

BINGO! EricW

I don't know, seems legit. After all there must be an abundance of powerline poles to aim at in the bush on a standard orienteering course.

Frigadee---I don't think that level of precision will be helpful in orienteering. For starters, the feature that you are using your compass to find might not be EXCATLY where it shows on the map. Mappers generally do a good job of getting things in relatively the right place but it may not be exact unless it shows up in the lidar or aerial or some other mapping aide. So, usually just eyeballig the direction relative to your compass is good enough.

I even heard that in some places (Sweden?) the magnetic north lines aren't even magnetic north but actually grid north. But they are deemed close enough that they just use them as magnetic north.

No pranks. This is an an interesting concept worth exploring in my opinion. To answer some of your questions -

jjcote - You are correct. I won't know what the needle is doing without a mirror but again, I don't want to use a sighting compass. I believe that if I hold the compass close enough to my body and just lift it up a few centimeters, it should be close enough...

EricW - looking through the sights is the next step after reading the map so I'm not sure what you mean by that

robplow - guilty as charged, I'm an American

And after all that - any design ideas?

I have heard this joke before. Other similar jokes are having extra long (like half meter) baseplate and having two baseplates, one in each hand for extra accuracy, and having compass attached to a heavy iron bar to make it not turn easily. Typically you hear these jokes when you ask someone's strategy for coming night race. Of course all af these are just jokes, in orienteering you do everything while running hard, imagining someone running with a heavy iron bar (with needle stuck to it), two compasses (with needles stuck to each other) or aiming like this in darkenss a branch 10 meters away at high speed is always hilariuos.

Carlch I think you are making an excellent point - adding sighting capabilities to a compass is just going to make the compass more accurate than the map can ever be.

Another aspect you don't mention is that mag north moves. In most places the annual movement is so small it does not have much effect - where you are it would take over 15 years to change by 1deg (assuming the annual movement does not speed up - which in fact it has been doing). But in Whitehorse (YT) it takes just 3 years to change by 1 deg. In places like that you need to have a system for updating the mag north on your maps regularly. My guess is that +-2 deg is accurate enough given all the other sources of error you mention but I I try to keep maps within +-1 deg just to be safe.

Also it is surprising how often I have come across O maps that have mag north wrong - just due to very basic errors not due to the annual drift. It might seem a simple thing to get right but it can actually be quite confusing and many very experienced mappers don't seem too understand it very well. And I have even seen cases where attempts to correct the error have actually doubled it - eg adding 3 deg instead of subtracting.

I think the situation in Sweden is that they orient the layout of their maps to grid north - but still the north lines on the map are oriented to mag north - this means the mag north lines are not parallel to the map border/paper edge as the IOF rules require. That can be misleading if you are used to assuming the north lines are parallel to the map border/paper edge - as most non Swedish orienteers are. But it does make it easier to update the mag north for annual drift: all you have to do is rotate the north lines. Whereas when the map layout is oriented to mag north you have to rotate the map within the layout and then probably rearrange the layout unless the rotation was very small.

But I have a feeling Sweden may have changed their rules on this recently - brought them into line with IOF mapping rules.

The first major map I ever drafted (30+ year ago, in the pen and ink days) was mostly fieldchecked by someone else, but a small section was fieldchecked by me. I taped the two pieces of fieldwork together and magnetic north on the two pieces was different. By a lot. I went out and took measurements on the other guy's piece, and it turned out that mine was right. If I hadn't done that extra section, I wouldn't have noticed the error, and the map would have gotten printed that way.

Anyway, Frigadee, you may have noticed that nobody seems to think your idea has much merit. That doesn't mean that it's not worthwhile to try and innovate. Build your gizmo and give it a try. However, I think it's a pretty safe bet that the people who have responded have a lot more experience than you do, and they understand that... well, that's not how things work in an orienteering competition. It depends on the terrain, of course. I did a 25 km orienteering course yesterday, in very technical terrain (5+ hours). How many times did I take a bearing? Zero. How many times did I use my compass? Several. I used it to make sure I had the map facing the right way, then I read the map.