Position: 41°12’57″N 13°34’23″E

About a month ago I realized I’d neglected to order electronic charts of the eastern Mediterranean for our chart plotter. The eastern Med apparently starts on mainland Italy. Without details, Aleta now sails across beaches and climbs mountains. Cool, but not helpful.

We turned to our smartphone navigation apps instead. Same data, smaller screen. After a couple of days we decided entering a new harbour using an iPhone as a chart plotter is about as intelligent as texting while driving in Boston. Phones are much fiddilier and invariably fall on the deck when you need them most. It’s a good thing sailing is much slower than driving.

A year into our adventure, I realized that Aleta would probably sink under the weight of all the paper charts we’d need for a circumnavigation. Either that or bankrupt us. So, we committed to electronic charts. A decision that, like anchoring, creates ructions in the online sailing community. The two camps – the “Good Lord! I’d never dream of going to sea without my trusty Admiralty charts!” Luddites square off pointlessly with the, “Dude, my Android tablet is way cool for charting!” crew. I suspect few commercial or military vessels have paper charts these days.

Tough Cookies

Practically all e-charts are based on government, i.e. naval, data. That the data may have been gathered by James Cook in 1770 and brought forward erroneously since then, is baffling. Especially, given the level of surveillance the world now enjoys. Google satellite images stay up-to-date and helpfully display where shoals have shifted. And despite billions of dollars invested in putting signal generators in space, there is still no substitute for a pair of binoculars and a spotter on the bowsprit.

With detailed piloting books and Navionics apps on multiple devices, we feel confident we have enough system redundancy to get from there to here safely. But, what if we got struck by lightning and all our electronics fried? Well, what if we had a sneaky rat eat through our paper charts? To avoid fried phones, we put all our mobile devices in the oven during storms and raise a toast to Mr. Faraday.

So Much for Paper

NOAA-chart-13246

The US government is doing away with paper charts in favour of electronic ones.* Because digital charts are more than up to the task, there’s even talk of doing away with physical aids to navigation – buoys and such-like. That would be a loss. After all, you’d miss the joy of discovering you’re on the wrong side of the wrong buoy if you couldn’t read a number off it.

Are e-charts perfect? No. Chart plotters make you lazy, and they’re no more reliable than Captain Cook’s boatswain until they’re updated. Worse, GPS signals are delayed and tell you only where you were a minute ago, not where you are right now. That’s not as big a deal in the middle of the ocean as it is in the mouth of a foggy tidal river. No matter how many GPS plotters you have, you still have to watch out when you’re on watch. Translating two-dimensional lines into three-dimensional reality is part of the fun of sailing. And should the solids hit the Faraday cage, you’ll be grateful for all that compass steering practice you had over the years, too.

* You can download PDF scanned images of official US charts here for free: NOAA Charts Catalog

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4 Comments

  1. Yup, I sort of stopped saying, “Hey, what if your GPS fails” when I realized that there are two or more independently powered GPS receivers on every vessel, plus one in every crew member’s pocket and often another on their wrist. But one shouldn’t forget that the WAAS enhancement is less fault-tolerant, and the GPS system as a whole is capable of “soft” (i.e. credible) faults when your unit is using a couple of sats too close to the horizon–that’s the best explanation I’ve run across.

    Unk

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