Of Maps and Sextants

This makes me happy.

Officials reinstated brief lessons in celestial navigation this year, nearly two decades after the full class was determined outdated and cut from the curriculum. That decision, in the late 1990s, made national news and caused a stir among the old guard of navigators.

Maritime nostalgia, however, isn't behind the return. Rather, it's the escalating threat of cyberattacks that has led the Navy to dust off its tools to measure the angles of stars.

After all, you can't hack a sextant.

Some years ago, I had a conversation with a US Army officer in which he opined that West Point should stop teaching map-and-compass navigation to cadets.

"Nobody needs that old stuff anymore," he groused. "We have GPS now. It's faster and more accurate."

"What happens if the GPS system goes down?" I asked.

"Not gonna happen," he assured me. Why he was so confident, I have no idea. My brother is an honest-to-goodness rocket scientist and he's not nearly so confident that the GPS satellites will survive in wartime against an advanced enemy.

"What happens if a soldier trips over a tree root and smashes his GPS receiver on a rock?" I asked.

Uncomfortable silence ensued.

"It'll always work" has got to be the least persuasive reason ever for not having a redundant system backing up your primary, and especially in a system on which people will be staking their lives. And the more fragile parts the primary system has, the stupider the argument becomes. Factor in an advanced enemy with a interest in breaking that primary system and not preparing redundant systems or skills should be considered an unforgivable dereliction of duty.

Maps, compasses, and sextants—all technologies that our ancestors developed when they had no access to computers or radio transmitters, and they worked for centuries under some of the worst conditions imaginable. They explored the globe with them and they won wars with them. They require no electricity (less batteries for a soldier to carry) and can't be hacked. They're the most indestructible navigation systems we have. 

"But what if I trip over a root and smash my compass? What if I drop my sextant overboard?"

With a little MacGyver-ish know-how you can make a basic sextant or compass out of common household materials. With those, a wristwatch, and a bit of astronomical knowledge and you can figure out where you are anywhere on the planet with a pretty reasonable degree of accuracy. They're so cheap and easy to build and learn how to use, I can't figure out why the military ever stopped teaching those skills in the first place. It's sure not rocket science.

Were I in charge of US military education, I wouldn't even begin teaching GPS navigation until soldiers and sailors had proven their mastery of the old skills first.

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If you want to read an excellent book on how one of those old navigation methods technologies was developed, I recommend Dava Sobel's Longitude. 

If you want to get really hardcore about learning how to navigate by the stars, you'll want your own copy of the definitive manual on celestial navigation— Bowditch's American Practical Navigator (first published in 1802). I've got a copy on my bookshelf and it's a beast. Bowditch is also available for free online, but I prefer the hardcopy version. After all, the time when I'd be most likely to need celestial navigation by the stars would also be the time when I could least count on my iPad working.