I use a Moscow Model 3 (Stable). I find this to be an excellent compass, not just for orienteering but also for NAV and MM events. It has a rotating bezel which is ideal for long legs on mountain navigation type events. I also use this feature on certain types of legs in ordinary orienteering.
SportIdent are doing a World O-Day special offer at the moment (at least it still appears to be available) where you can buy a "school" SI Compass consisting of a Moscow thumb compass with built in SI card (20 punches only) for EUR22. This is a less specialised compass than the model 2 or 3 type but should still be a good general all-round compass. I have one but have only used it once so I can't really give a review of it at the moment. Details at https://www.sportident.com/wod.
With regard to John's points I think most orienteers hold their map in their off hand and use their dominant hand for punching with their SI-card. The greater dexterity in the dominant hand generally makes punching much more fluid with that hand while the other hand is free to keep track of the position on the map, and the map and compass don't get in the way of punching.
This raises the interesting question of what happens when using an SI compass. I don't have an answer to that question and I only know one person who is using an SI compass regularly in Leinster, so I don't have much data to go on. I'd be interested to hear other people's experiences with the SI compass.
You could of course just use the SI compass as a compass and continue to use an SI card. My current thinking is that there isn't an advantage to having the SI card and compass combined and in fact it is a disadvantage for the following reasons:
- The card, compass and map will all be in the one hand and the whole shebang has to be used to punch whereas with the usual arrangement, with practice, one can punch and continue essentially unterrupted to read the map.
- The compass has to be positioned in just the right way to punch which again breaks attention from the map during punching. With a regular SI card, again with practice, if you position your hand in the right way then the card is pretty much guided into the hole for punching and this becomes almost a reflex which takes no conscious effort and therefore doesn't break concentration while punching.
I think that our system of positioning controls in this country is part of the problem with this. There is little doubt in my mind that it is more more akward to position the compass correctly for punching when the control is vertical rather than horizontal. Never mind that the intended positioning of the control boxes is horizontal. Every international event I have attended has had the controls positioned horizontally and SI themselves have started selling specially designed control stakes which also position the control horizontally. These are thin and lightweight fibreglass stakes that take a standard SI control baseplate. I hope to get Ajax to get some of these to try. While much more expensive than electric fencing posts I think they potentially have a lot of advantages.
It would be interesting to have a survey of the compasses used in Leinster by regular orienteers. I had assumed that the Moscow compasses were currently the dominant model but I haven't looked that closely to see what people were using. Certainly, up until 2000 or so the Silva compass was dominant. Anyone want to set up an online survey?
Looking at the current Silva product pages I notice that their thumb compasses don't have any scale along the direction of travel edge. That's a pity as I find that indispensible in the Moscow compass. Some of the Silva thumb compasses also feature what is known as the Spectra System which divides the bezel into twelve regions identified by colours and black dots. Essentially you have yellow (no dots) yellow (one dot), yellow (two dots) etc. There is a video here https://www.youtube.com/watch?v=h1w1mqVF-2c, that shows how it's intended to work (bizzarrely, the Silva web-page doesn't seem to have any information on it!). My reading of it is that it's intended to be a kind of idiot-proofing of the task of taking and following a bearing. Unfortunately there are a lot or problems with this, not least of which, is the idea presented in the video, that you take a bearing, then take your compass of the map to follow it. That is just wrong! It's also too inaccurate an approach for bearings in orienteering in my opinion. I'd be interested to know if anyone is actually using this system and what their experiences are. I would personally dissuade novice or junior orienteers from adopting it in favour of the standard approach to the use of a thumb compass. I'm happy to be convined otherwise if I'm wrong that this is actually a great approach to compass use in O, but I doubt it!