I am a bit sorry if I wandered a quarter-mile off the track of the discussion, Gavin, but given the other responses your topic drew out, I felt motivated to speak for both Electronic and Traditional navigation. No versus intended, even though my bias is obvious.

My sermon got some of its fuel, when I listened to one skipper's story... Both his GPS units failed at sea. With heaps of sea room and no other damage, he responded by setting off his EPIRB. Wrong action. Or was it? He spoke as if anyone would do the same.

Whether it's the US military or my iPad screen or GPS antenna that fails, I'm for having an independent, reliable backup ready, and carry on with the the cruise. Lightning, don't melt both my sextants.

Kurt Jon Ulmer wrote:

Traditional navigation, (with sextant & tables, paper charts, hand-bearing compass, watch, plotting tool and to be complete, a trailing log) can still be used almost whatever happens. You need to practise. Accuracy can't quite compare, so better sail conservatively. Charts are desk-size and they can be written on. Dividers are useful - 2, 4, 6, 8 miles. All the methods are 1890s-chart-compatible, once you sight land.

What if I had to choose only one way? 

No question. Traditional. But.........

Using traditional methods, our eyes, ears and nose, we gain an understanding of our surroundings that will help to keep us in charge when things begin to go awry. And remember the rule of thumb: put your thumb on the chart and keep that distance off.

In Praise of Traditional and Electronic Navigation

I think everybody should carry the gear for both, and be ready to use either. You probably do, and you probably are. This is a sermon for someone who doesn't, and isn't.

Electronic navigation aids are accurate and wonderful. Extra-sensory perception that allows us to thread tricky channels in colour, in fog, in the dark, in shelter. Bit small, charts viewed a screen-size at a time. And, the components can fail from many causes, or be turned off by someone else.

Traditional navigation, (with sextant & tables, paper charts, hand-bearing compass, watch, plotting tool and to be complete, a trailing log) can still be used almost whatever happens. You need to practise. Accuracy can't quite compare, so better sail conservatively. Charts are desk-size and they can be written on. Dividers are useful - 2, 4, 6, 8 miles. All the methods are 1890s-chart-compatible, once you sight land.

What if I had to choose only one way? 

No question. Traditional. But in happy reality we can have have the luxury of both, each a complement and backup to the other. 

Which is more in need of a backup?

Things each system depends upon:

Electronic - things like batteries & charging them, US Government, exclusion of moisture, Microsoft/Apple/Google/Intel, many tiny electrical contacts, much software and its updates, someone's having geo-referenced correctly from mixed sources (e.g. Ha'apai Group, Tonga) to a modern datum, without a depth survey...

Traditional - things like magnetism, geometry, arithmetic, a book or two, the Sun and Moon, and a quartz watch (for a proper longitude such as Captain Cook never had) and a good clear view.

But besides all that excellent logic, which is easy and nearly safe to disregard nowadays... 

Why ever would someone build a junk rig from scratch and take it to sea, only to be stupidly lost if they happen to 'brick' a 'device?'

I have been using electronic navigation systems for almost 30 years now. First the old Satnav system, and then GPS. Luckily I served my navigation 'apprenticeship' doing navigation the old way with a chart and a hand bearing compass, and also learning the cautions associated with navigation. I have to say though, that in my years of using GPS Chart plotters I have found them to be 100 percent accurate. I think that accuracy will depend on the quality of system used and the source of the charts. I have used Navionics, C Map, and the proprietary Garmin electronic charts. My experience has been in Tonga, New Caledonia, Tahiti and Australia, and of course New Zealand. During our recent time in New Caledonia and navigating through the reef strewn Southern Lagoon I found the plotted positions of even minor small coral reefs to be accurately shown on the chart plotter. I now use and rely on electronic chart plotters on a daily basis in my job as a skipper of fast ferries and have found for example the positioning of navigation markers to be incredibly accurate. The two ferries I drive have Touch Screen Simrad plotters which I have found very easy to use and allow us to operate in hours of darkness, in what are quite narrow channels,  at our service speed of 20 knots, which is a lot of boat and people moving at high speed. The chart plotters are coupled with Radar and I find the radar overlay on top of the electronic chart to also enhance the accuracy of navigation and confirm the accuracy of the electronic charts. 

Of course if anyone is navigating in remote areas and approaches to coral reef passes are anticipated then approach should only be made in day light hours when visual confirmation can be made of the chart plotter information. But of interest, when entering both South and North Minerva Reefs in the South Pacific not that long ago the Chart Plotter positioning and information was completely accurate.   

Yachting Monthly has just published an article which is about using satellite imagery to check navigation. What it highlights is something that should be of keen interest to JRA members who sail to less-frequented parts of the world, which is that in some areas the charts are up to 2.2 miles in error. 

I believe that quite a number of people using modern navigation aids such as GPS and chart plotters have complete faith in the accuracy of the data, not realising that underneath all the modern digital wizardry are charts sometimes based on surveys from the 1870s, made with sextant and lead-line, and that the errors that result can be significant and dangerous. 

Tom Partridge, the author, records discovering that in Fiji's Lau Islands the charts were "up to 0.56 miles out, a critical difference when you're targeting a safe entry"

The article goes on to describe how satellite images such as Google Earth can be used to check/verify/correct such errors; the link is

http://www.yachtingmonthly.com/sailing-skills/how-to-make-navigation-safer-using-satellite-images-34665