Pace Count
 

Good point lets start a Land Nav thread.

When you are developing your pace count you should;

a. walk a flat 100m and do a count.
b. walk in rough terrain 100m and conduct a count.
c. walk in rough terrain with ruck and gear 100m and perform a count.

Do not become transfixed with pace count. Learn to read a map blindfolded.
Learn how to recognize terrain features and to associate those terrain features you are seeing with the map you are carrying.

The Team Sergeant

I've had brief instruction in underwater navigation for diving. What, if anything, is different on land?

You talking about surface or sub-surface navigation?

I'm sure one of the SCUBA guys can give you a reply. Combat Diver was not one of my specialties.

I think you should pace count for klicks and not miles. Use the metric system, that way when you do it in another country, you'll be set. Plus its easier.

Re: Pace Count
 

Thanks Team Sergeant,

Your advice will be taken; I am joining a local orienteering club and will practice. At night though the pace count will be important.
To determine distance as you walk through various contour lines is there a trick?

Here is a scenario. You are in a jungle or heavy forested area and you can not see terrain features at a distance. You shoot your azimuth, and you start moving out. The terrain differences are subtle and make it hard to know exactly where you are at. The distance on the map from point A to point B is ten km as a bird flies. Question is you have numerous elevation changes, how do you determine walking distance?

Thanks,
Mark

Re: Re: Pace Count
 

Good question Mark, now I have one for you.

Did you learn to run before you learned to walk?

In order to successfully navigate through a jungle one should have an advanced understanding of map reading and more than a beginner’s level of experience. You must incorporate all aspects of land navigation, pace count, route selection, map study etc. before one tries to tackle a triple canopy jungle. One discipline alone will not get you through the scenario you posted.

Learn the basics before you head out on the advanced skills trials!

If you think it is daunting navigating through a jungle, try the abovementioned scenario while watching for booby traps and enemy soldiers.

The Team Sergeant

Hi,
I rewrite the answer I gave in the fieldcraft thread:

I count approx 115 pairs (easier to count 2 paces than each) for 100m of forest.Thats because I avoid obstacles.On a road I do approx half less paces.But this is for me, for you it will changes.So you have to try.Very easy to found your paces with a GPS.
I use a little rope and I attach it to a button hole.Every 100m I add a node.

Roger that Team Sergeant, on that note I'm going to turn off this computer and go running.

Thanks,
Mark

Subsurface.

Pace Count
 

Pace counts are still useful, remember, a navigator seeks every piece of available information to determine his position. Here's the procedure I used/taught:

First, start with at least 400 meters of flat level terrain, preferably in a square (To equalize slope). Walk the perimeter, counting your steps. Divide by 4. That is your base pace count for 100 meters. (Let's assume it's 135 steps per 100 meters). Write that number in the little green memorandum book in your shirt pocket.

That is the LOWEST pace count you will ever have. Why? Because it was daylight, you are fresh, with no load, on level ground, in good weather, etc. From then on everything else will increase your pace count.

Night - You will take shorter steps, and will wander more. That means more steps to travel 100 meters.

Loaded/Tired - Your steps will shorten and you will tend to look down. You won't follow an azimuth as accurately. Result: even more steps per 100 meters.

Uphill - You will take shorter steps, and you will be traveling a greater distance than what a point to point measurement on a map would indicate. (The hypotenuse of a right triangle is always the longest side). On a 30 degree slope, moving 100 meters as shown on the map requires you to march 115 meters over the ground. Also, you will tend to "cut the contours" (zig-zag) and that will increase travel distance. For the same reason, even traveling downhill will not usually result in a lower pace count than your base count, and may even be greater than your base pace count.

Rain/Snow/Soft soil - All will cause you to shorten your step, and than means more steps per 100 meters.

So, based on experience, you will begin to keep a list of pace counts in the back of your memo book. It might look something like this:

Base = 137
Ruck/LBE = 145
Night = 150
Tired/Ruck/Rain = 155
Uphill (shallow) = 160
Uphill (steep) = 175
Max (Night/Ruck/Tired/Uphill) = 200

You will adjust as you go. For example, assume the first leg of a rucksack march causes you to cross a road after 400 meters. You start with a estimate of 145 steps per 100 meters. After traveling 400 meters (4 knots in the pace cord), you have not come to the road, but you see it in front of you. Continue to count steps as you cross the road. Let's say that was 20 extra steps. Hmm, must be a little more tired than you thought. 20 steps, divided by 4 = 5 extra steps per 100 meters. Next leg, use a pace count of 150 per 100 meters. After a while, you will get surprisingly accurate in measuring distance in all kinds of conditions. Your notes will help you, and your men will trust you.

If you are keeping pace for sport navigation (orienteering), the same rules apply, but you will find it useful to count every other step (such as when your left foot strikes the ground). That way, you can add a Running pace count for cross country jaunts from control to control at a jog. The numbers will be about half that of counting every step, but again you will want a base count, followed with adjustments for weather, exhaustion, slope, etc.

There are several ways to keep track of pace, but my favorite is the simple ranger technique of a boot lace cut off and tied through the top buttonhole of the shirt, allowing the end with the little plastic thing at the tip to hang down about belt level. After traveling 100 meters, tie an overhand knot near the top of the string. Next 100 meters, tie another knot. In between knot-tying, curl up the string and stuff it in a top pocket. Day or night, slide your fingers down the string to count the knots/100 meter segments. When you get to the destination, untie the knots.

And now the bonus question:
What's the correct name for the little plastic thingies at the end of boot laces that keep the end from getting frazzled?

That is some great information, thank you CSB.

Mark

Hey SCUBA dudes.... Some thoughts on underwater nav?

Sorry for being late Team Sergeant....I have No Excuse.

Differences between U/W and Land nav.

First off, on land you don't have to worry about running out of air. Now that that's out of the way, on to more serious examples.

U/W "land marks" and features tend to look the same, whereas on land once you get a land mark in the back of your mind, you can more easily ID it. ***Of course under Ideal conditions*** But even under less than Ideal conditions, you have a better chance of picking up a land mark, while on land.

U/W you are really hampered by only a few set of measuements, as oppossed to the ones that CSB posted above.

U/W you have : (using 100 meter measurements)
Kick Cycles
Elapsed Time
Tank Pressure
Arm Spans
Measure tape or line

Kick Cycles are measured by each leg completing one kick. This is best when there is unlimited viz and NO current to deal with, also the type of equipment that you are using/wearing. That can throw off your streamlining.

Elapsed Time is measured just by using the time it takes you to swim a given distance (100 meters). But the disadvantage of using this method is again having to deal with currents and if you stop for any reason, it'll throw off your pace.

Tank Pressure is used for more of a longer distance traveled. At the same depth and activity level, tank pressure drops at a fairly even rate. Disadvantage again is having to deal with currents and if you change your depth or activity level, your air use will change.

Arm spans are the most accurate measurement, next to using a line or measure tape. What ever the conditions that you are in and what ever activity level you're at, just reaching out and pulling yourself alone the bottom, is the best way to measure distance, next to using a tape or line.

Measure tape or line is the most accurate measurment, but difficult for long distances. It's used primarily in wreck diving, cavern/cave diving, search and recovery diving and when high precision is required.

Using a compass U/W takes practice. Even though it may "feel" wrong, trust in your compass. But the one thing that you must be warry of when using a compass U/W is you must watch out for your depth changes. A diver will get so engrossed in thier compass, they will actually being to assend upwards. That's why it's important for your buddy to be with you when doing U/W compass navs. You can concentrait on the compass and your buddy can watch the depth for you and let you know if you are assending or even desending.

Underwater Navigation
 

In a word, it's hard. Currents will play havoc with swimming a straight line. Even if you are accurately holding a compass heading, the drift will traverse you sideways.

As noted above, distance measurement is fiendishly difficult.

Here's an old tool I used "back in the day" to try and figure out where I was going and the most direct route back from a wreck dive:

http://members.aol.com/cbjpegs/scubanav.jpg

It worked like a pilot's E6B computer, rotating the dial to align azimuths under a fixed grid.

In general, I considered it good work if I could just hold an azimuth and hit the beach within 20 degrees of my intended arrival point. we didn't have modern "consoles" so we used wrist mounted compasses. Mine was on my left wrist. When trying to hold an azimuth I would extend my right arm straight ahead, then grab my right elbow with my left hand. That put the compass in front of my face. I would try and keep the compass needle centered while swimming forward with flutter kicks. It helped to find landmarks on the ocean floor by sighting a line off the extended right arm.

Virtual Land Navigation
 

I was taking correspondance courses online, and I came upon a Virtual Course that read "How to set up an Observation Post". Afterwards I took another small course on Land Navigation, and the thought came to me, Why not try to build a Virtual Land Navigation Course? After doing a few searches on here, I didnt see anything about the topic.

What does everyone think?