Why north at 180 degrees?

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

I applaud the OP for posting the question, because the diversity of response is revealing. Compass navigation may seem to some to be perfectly simple and straightforward. But, to others - intelligent, educated individuals - it seems obtuse at best. As a parallel example, one of the biggest challenges for pilots during instrument training (and beyond) is mastering the concepts of headings, bearings, relative bearings (and bearings TO and FROM a navigational aid). And lot more time is spent on compass navigation in instrument training than in dive training. I learned compass navigation decades ago, as a Boy Scout, and have had the need and opportunity to use it throughout the years since then and, in doing so, continue to develop some modest level of proficiency. But, I consider myself to still be learning new techniques, and I still catch myself making mistakes. Many divers, and instructors (and DMs, AIs, whatever) learn ONE WAY to use a compass, possibly because their instructor only knew ONE WAY to use a compass, and essentially they memorize how to do it, possibly without a full understanding of why they are doing it that way, or what they are actually doing. Then, they teach that ONE WAY to others, who also memorize how to do it without understanding. And, when students ask 'Why am I doing it this way?', the response is too often, 'Don't worry about it. Just learn it this way, and you will be fine.' My personal bias - the average educated adult in the US couldn't use a compass to navigate from one point to another, on land, if their life depended upon it. Yes, divers get additional training, but they are still a subset of the general population.
I think the original question has been answered. The question was serious, and I doubt the question arose because the OP wasn't properly trained. Actually, I suspect that others have had the same question, but were afraid to ask it. The timing of the post was also interesting to me, because I was just thinking last night about what to do in my NEXT AOW class, to help divers better understand compass navigation, based on an experience I had in my LAST AOW class several weeks ago. The variety of responses, and the variety of approaches to answering the original question, have been very helpful to me in that regard. So, rather than presuming the OP was making a joke, or asking a dumb question, or was not properly trained, it might be useful for all to reflect on how we use a compass, how facile and versatile we really are in that use, AND how we teach others. Just a thought.
 
What's a compass?

It's an instrument, usually in a console but sometimes wrist mounted, that takes you from where you are but might not bring you back. Or it takes you from where you thought you were and gets you more loster:D
 
Also, can anybody suggest a compass with a window through which it's easy to reading the bearings? The Dive Rite one I have now apparently doesn't work for me. Thanks.


I'd suggest the Suunto SK-7 compass. The main reason why is that it allows for a much larger degree of tilt before it binds. Meaning it doesn't have to be perfectly level to work right.

I have the Suunto and when I'm navigating I never look through the stupid window.

I didn't see this technique mentioned above.

Making sure that the window of the compass is facing you, rotate the bezel so that the number, bearing, you want is on your lubber line. If will be the number that is opposite your window. Moving your body, not the compass, get the 'mouse in the house'. What that means is that your bezel has three notches on it that are opposite from each other. Orient yourself so that the North arrow is in between the double notches. Keep the North arrow in those notches and your on your bearing.

You look at this from above. The closer you are to looking straight down on it, the more accurate you will be.

If you're not sure if you're doing this correctly, lot at it through the window to confirm.

If you need, I'll post a picture.
 
My personal bias - the average educated adult in the US couldn't use a compass to navigate from one point to another, on land, if their life depended upon it.

I don't think you have a personal bias on this one. I would comfortably say that very few folks out there really know how to use a compass. Most people don't need to. Now with GPS becoming so affordable, the skill is further diminishing.

I've even found that most folks have no idea that there are actually three Norths out there: True North, Magnetic North, and Grid/Map North.

I've found that most people have no idea what declination is and how to compensate for it.

I've even seen civilian land navigation competitions where they set their waypoints without declinating their compasses and telling the competitors not to declinate their compasses.

I was a Forward Observer in the Army for 10 years. I would call for and adjust indirect fires, air strikes and naval fires. If I wasn't good with a compass I'd kill myself, friendlies, civilians, or miss the target entirely. I consider myself competent with a compass.

I commend the OP for posting your original question because I guarantee there are A LOT of divers out there that really aren't that good with the compass.
 
Also, can anybody suggest a compass with a window through which it's easy to reading the bearings? The Dive Rite one I have now apparently doesn't work for me. Thanks.

Suunto SK7 in the DSS bungee mount.
 
There are "Direct" and "Indirect" compasses. Neither of which require you to read the side window used for taking an azimouth (sp?).

It is a matter of when you hold the compass in line with your body is how the bezel and the needle (arrow) interact to tell you the heading you're on.

I assure you, you don't have to travel looking at the side window of the compass.

If you're heading south the needle will be pointing back at you. If you put the North (or "0"/"360") on the north tip of the arrow, it will put the heading you're on at the end of the compass as aligned with your body/direction of travel.

In the other type of compass, as you're travelling the arrow will point at the relative heading of travel if you keep the compass aligned with your body. You do not need to spin the bezel.

I know that trying to explain this without graphic aids may not convey the information well, but that's the best I can do here.
 
And by the way, my 21 years in the Army hasn't caused any confusion in handling compasses (as a poster above suggested). I regularly had to use a compass and map to report back my location within 33 feet2 (10 m2) and to travel long distances at night. Navigation is navigation. Until I had a good instructor teach me how to CORRECTLY use a compass I too had issues with them.

I've seen a few scuba instructors who didn't understand the fundamentals of navigation and teach their students some very wrong information. Of course, that propagates, and the whole concept of navigation just gets more convoluted than it ever needs to be.
 
Last edited by a moderator:
And by the way, my 21 years in the Army hasn't caused any confusion in handling compasses (as a poster above suggested). I regularly had to use a compass and map to report back my location within 33 feet2 (10 m2) and to travel long distances at night. Navigation is navigation. Until I had a good instructor teach me how to CORRECTLY use a compass I too had issues with them.

I'm not really sure where I said my military experience had or would cause confusion handing a compass.

I believe I was trying to make a point that a LARGE portion of people out there don't know how to use a compass or know the fundamentals of navigation, including those who teach the skills.

The way you wrote your post, I'm surprised that it took you leaving the military to finally learn how to correctly use a compass. I must remember that REMF's play a valuable role in combat operations.
 
Another recommendation for the Suunto SK7 compass in a DSS boot. Works well.

Henrik
 

Back
Top Bottom