The Ultimate Navigation Manual is the Bible of outdoor navigation.

I’m not exactly a navigation wunderkind but I know my way around knowing my way around the outdoors: I was an assistant instructor for a navigation course during which I managed to accrue an error of only six feet after a one-mile straight-line navigation challenge through a forest thick with deadfall. Throughout the years I’ve picked up various navigation tidbits and techniques not just from taking or teaching classes but from trip companions, the musings of outdoor luminaries, and of course books on navigation. Little did I know that I could have found everything I’ve ever learned – and a whole lot more – in one location: the Ultimate Navigation Manual. Whether you’re an expert or just starting out this is the only navigation book you need.

If I had to lodge a complaint it would be with the lack of certain photos. For example, there’s a section which discusses how the reflected colors of clouds change depending on whether they’re above snow, water, or land. That sounds like interesting knowledge but without pictures to illustrate the difference it’s impossible to translate into real-world use.

What I Learned

  • A radial arm is any visible object whose position or orientation can be referenced to cardinal directions on a compass
  • You can use regularly spaced tape (or length measurements) on a pair of trekking poles to estimate slope angle
  • If you know the prevailing wind direction of an area you can use windblown trees as radial arms
  • You can estimate wind speed by analyzing the distance between 4-mb isobars (there are equations for this online)
  • The temperature decreases between 3 and 6 degrees Fahrenheit for every 1,000 feet of elevation, which humid climates tending towards 3 degrees and drier climates 6
  • Cupping your hands behind your ears greatly increases your directional hearing
  • If you know the general direction of flight paths through an area then you can use airplane contrails as radial arms
  • Turning around and taking “back-snaps” as you hike in, whether mentally or with an actual camera, can greatly reduce disorientation on the return trip
  • The sun and moon move a maximum of one degree every 4 minutes and as a result can be used as radial arms if you have nothing else to sight
  • In forests where the sun isn’t visible you can instead use shadows as radial arms
  • You can see 30% farther to the horizon while standing vs. kneeling
  • Your night vision is 10,000 times more sensitive to light than your day vision. After 7 minutes of darkness your night vision is at 30% effective but it takes 30 minutes to reach 100%
  • Satellite dishes (DirecTV, etc.) point towards the equator
  • Quadrifiliar helix antennas such as those found on the Garmin inReach Mini work best when oriented vertically or at most 45 degrees off of vertical, not flat
  • In the event of GPS multipathing you can either cup the GPS receiver in your hand or position your body between the receiver and the reflective surface such that the reflected signal is blocked (would have been great to recall this on my recent Davis Peak trip)

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