Saturday, July 02, 2011

Night Navigation - Trekking

There are 2 Pangea night races coming up; Luminescent and Nocturnal - so to help new folks out in preparing here are tips for night navigation. This is part of a 3 part series on trekking, biking, and paddling at night.

Trekking

First - you need some really good lights, everyone on the team should have a decent headlamp and also one good hand light. Invest in decent lights - if you buy cheap lights you will end up spending more money as you replace them. The Inova Bolt is my favorite. It does take CR123 batteries which are expensive if you buy them in a store. I order these bulk online from http://www.cr123batteries.com/ for less than $1 per battery. You also need a decent headlamp, I use primarily the Princeton Tec Apex - it is a marvel in brightness and runs on CR123 batteries also. I can run all night on low power and the beam mode lights up the night.

OK - so now you have all the lights are are ready to head out on your trek. First - everything looks different at night. What is an obvious trail during the daylight hours will likely be nearly invisible at night. Also you will have natural tendency to "circle" at night. Without a compass or a trail to follow nearly everyone ends up making circles. This means you need to be more conservative in your navigation. The best thing to do is find and follow handrails if at all possible - even if it takes you a little out of your way. (Handrails are linear features like roads, trails, streams, etc...). The navigator also needs to communicate more with the team at night - I find that a team member who might be nervous about the nav in the daytime is more so at night. Talking through the navigation plan does 2 thing - makes the team more comfortable and it may even help you avoid mistakes.

Some of the things that are important in the daylight are even more-so at night. I always preach "time and pace". If you are following a linear feature (or not) you should always have a good idea of how far you have gone. I use kilometers and will give an example here. A team walking quickly through the woods can travel about 1 km in 10 minutes. The maps are almost always gridded off in UTM coordinates - which are 1 km square blocks. I have talked to lots of teams that tell me how they walked for 45 minutes before realizing they went too far (and have made mistakes like this too). If you are looking for something 1 km away it will not take you 45 minutes (unless the terrain is horrible) to get there. So at each feature where you know where you are announce to the team something like - "It is 1:37 AM, we are looking for a small trail in this direction less than 1 km away, we should see it before 1:47 AM". This involves the team, reinforces your navigation plan, and gives you a goal. 

Here are some common mistakes in night trekking;

1. Diverging off the trail - because trails become very indistinct at night, it is very easy to lose the trail. Our team travels with a little distance (about 20 feet) on the these trails. If it is a marked or blazed trail - if you feel nervous about losing the trail, call out "last mark". Everyone looks for the last mark.

2. Heading for the light - I've seen many teams do this, they see lights from another team and immediately start walking towards them. Most of the time the team they are going towards is on another control or simply lost - and now you are lost too. Stick with your plan and race your race. (It is very hard to avoid the temptation on this one).

3. Single set of eyes - At night the team needs to help the navigator look for features (and the navigator need to let them know what they are looking for). The reason is very simple. The navigator will be looking up and down at the map. Every time they shine the bright light on the map, they destroy their night vision and ability to see terrain features. Odds are they will miss it simply because of this fact. Involve all sets of eyes in looking for features.

4. Fading in and out - In long races most teams make huge errors at night while racing because they simply "fade out" and go into zombie mode. When a team-mate starts mumbling "brains, brains..." they may have become a zombie and you may need help get the team awake.

Next up ... Biking at Night

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