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January 2013

Navigating the Muskoka River X

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In the spirit of wilderness, back-country tripping and expeditions the Muskoka River X will require traditional forms of navigation. Navigation will occur solely by map and compass. Maps will be provided to teams in the race package and are the only maps permitted on the course. The maps will be marked with checkpoints 1, 2, and 3, as well as the start and finish however all other obstacles will need to be plotted on the maps by teams. Upon registration, each team will receive the required 1:50000 topographic maps of the course, as well as course instructions. The course instructions will provide narrative detail of the course, along with 6-digit UTM grid coordinates associated with various way-points and obstacles. After receiving the course instructions and maps, teams will then review the course instructions and plot their planned route on the maps. It is the responsibility of each team to correctly plot the coordinates on the map as well as determine the route that the team wishes to take. Teams will then use their route as plotted on their map to navigate the entire 128km route, using only the map and compass.

Note: Any team found using maps other than those provided, or a GPS-enabled device that supports navigation may receive a time penalty or disqualification from the official rankings: Any device that is programmable with coordinators / way-points / topographic maps for the purpose navigation aid is not permitted. Any device that does not allow for the pre-programming of coordinators / way-points / topographic maps but is a GPS enabled device that allows for route tracking, speed, distance, pace, heart rate monitors, and time is permitted.

Now, for some of you, this may sound intimidating. In actuality, the navigation requirements are quite straightforward and we fully expect that no team will get hopelessly lost. Most who have ventured “off the grid” for any amount of time, or have followed any basic map should have no difficulty.

For the most part, traveling during daylight will be straightforward with teams relying on “line of site” navigation, with intermittent compass checks. For example, as you leave a river and enter a lake you look at your map that tells you to paddle east as far as you can go, into a bay. At the end of the bay there is a river, which you want to follow. So, after you establish your orientation with a rough compass check you visually establish your preferred route using obvious land features, cross-referenced with features indicated on the map. You orient your boat east and paddle east, checking for the various land features that tell you where you are on the map. Eventually, you reach the end of the lake, and make your way into the bay. Once in the bay, you visually see the entrance to the river you want to travel along. In this way, navigation is quite effective in making sure you get where you want to go. With line of sight, essentially you look at the map, look at the land features around you, and “follow your nose”. Little compass work required. Line of site navigation will form the majority of the race and will be useful in getting teams through Fairy Lake, Lake of Bays, and the North and South Muskoka Rivers: For the river sections, just follow the river!

Things will change a bit when night falls: Anyone who has navigate in the dark using a map and compass knows how disorienting it is. Because it is quite challenging to rely on land features for reference points in the dark, you are placed in a position of needing to trust your maps, route coordinates, and compass. With that in mind, the most challenging stage from a navigation perspective will be Stage 4. During Stage 4, teams will travel 6.8km, south to north, on Mary Lake in the dark, making their way to the mouth of the Muskoka River. When paddling across open water at night distances are hard to estimate, shorelines are challenging to follow and land features can all but disappear. And if it is cloudy or there is no moonlight, then it really is only you, your map and compass, and your lighting system. It will be during the Mary Lake crossing of Stage 4 that teams will need to rely on their map and compass navigation skills the most. With that in mind, here are the basics that you will need to know in order to plot UTM coordinates on a 1:50000 topographic map, as well as the basics for plotting a route and using a compass.

UTM Coordinates and Topo Maps

1. Topographic maps are broken up into squares.

2. Each side of each square is numbered, with numbers indicated along the sides of the map.

3. When a horizontal and vertical number are combined (where they intersect), they form a 6 digits UTM coordinate.

4. The 1st 3 numbers of the UTM coordinate relate to west-east. The last 3 numbers of the UTM coordinate relate to south-north.

5. Each grid (square) is exactly 1km by 1km (2 cm by 2cm)

6. 1cm = 0.5km OR 5mm=0.25km.

7. Example of UTM numbering is seen in the map below with the numbering sequence of 43-44-35 representing a west to east orientation and the 34-35-36 sequence representing a south to north orientation.

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8. A 6-digit UTM representing the west-east number by the south-north numbering is seen in the example of 445345, as represented by the dot on the map.

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9. In this example, the first two numbers, 445345, tell you the west-east “square” you are in along the 34th line. The fourth and fifth numbers, 445345, tell you the south-north line you are in along the 44th line. Each grid (square) is broken up into 1/10ths both west-east and south-north. The third and sixth number, 445345, represent the 1/10th fraction of the 2cm by 2cm square. In this example, each “5″ equals 1cm west-east and 1cm south-north, or ½ of the square.

10. Therefore, place a ruler west-east. Locate the 44th line and then divide the square in half by 1/10ths, moving towards the 45th line. At 5/10th (1cm) make a mark on the map. Draw a south-north line on the map crossing over the mark you just made. Now, place the ruler south-north along the 34th line. Divide this square in half by 1/10ths, moving towards the 35th line. At 5/10th (1cm) make a mark on the map. Draw a west-east line crossing this mark. Where the two lines intersect is where the UTM is located. Congratulations! You have just plotted a UTM Coordinate.

Compass Headings

1. Repeat the above process for UTM 453330.

2. Draw a line from point A (445345) through point B (453330).

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3. Take your compass and turn the dial so north in oriented to the top of the compass.

4. Place the compass on the map so the compass grid-lines are matched with the topo grid-lines, north-south. Make sure the center of the compass is over top point A; your starting location.

5. Your compass bearing is the direction where the line crosses through the compass dial, in the direction of point B.

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6. In this example, the route that you wan to follow is 154 degrees (south east).

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Using Your Compass

Without getting into too many technicalities, north on your compass is not actually north. Because of the magnetic field, the needle in your compass actually gets pulled west or east depending on where you are located on the Earth. When your compass needle is pointing north it is pointing towards “magnetic north” and not “true north”. “True north” is the real north that you want to be heading since it is the north that is represented by the grids on your map. The difference between “magnetic north” and “true north” is called declination. In Muskoka, the “declination” is roughly 11 degrees West of true north. Therefore, when you want to travel 0 degrees north, your compass will actually be pointing 11 degrees west. If you do not make an adjustment for this you will travel 11 degrees west of your destination, essentially in the wrong direction. To understand how to account for this, I recommend watching a great video that explains declination in a very simple way.

So, after watching the video, you know recognize that the actual compass bearing for 0 degrees north, at 11 degrees West declination, is actually 349 degrees on your compass.

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When using your compass to travel 0 degrees north, make your adjustment on your compass to account for the declination. Hold your compass at face level and look down the compass so that the needle aligns with the North arrow: If you have a mirrored compass (which I recommend), fold the mirror towards you so that the reflection in the mirror is that of the compass face (see photo). The direction that the compass is pointing is the direction that you want to travel. It’s that easy!

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Hints: Mirrored compasses also have sighting marks on the folding mirror, making it easier to landmark your destination more accurately. Also, I recommend purchasing a compass that has an adjustment for declination built into it, the same as the compass in the photo. In this way, you adjust your compass to account for the declination in advance and then use true north bearing on your compass for navigation instead of having to do manual adjustments every time you take a bearing. It’s worth the extra few dollars.

Hope this helps.

See you in September!