Traditional or digital navigation - which is safer?

[Bycrick]

Yes, I do remember the Yeoman. I actually tried one out. I remember thinking that is was almost the worst of both worlds. What I engineered in my mind was what the current chart plotter systems do. It reminded me of a quote from a software design book: You can’t cross a chasm in two small leaps.

[Paul L]

Originally Posted by tkeithlu

"A chart plotter is a wonderful device. And I use one. But I always have a paper chart and conventional nav tools aboard and ready, just in case."

Hamburking is right. Chart plotter, sure, and spare GPSs. One in the spare we use for position and speed, one in the AIS, a couple more here somewhere. But, a paper chart with lat/lon updated at 30 minute intervals. Take it right off the GPS. Then when you are hit by lightning, and lose everything electric, you know just about where you are and can do it the old way home.

Why plot it every 30 minutes? Why not just enter it into the log on a periodic basis. Then plot it on the once in 20 years that you run into a failure.

[Bycrick]

BruceK also hits it right. Finding the west coast of the US isn’t a challenging problem. But going the other way is a different kettle of fish. Remember that Magellan sailed from the Horn to the Philippines and never saw any land. Different levels of precision are necessary for different conditions.

[Dsanduril]

I have a friend who is a very high-end instrument and cabinetmaker. He had a client who was sorely disappointed one day to see this highly paid craftsman putting holes in his "hand-built" bespoke cabinets with an electric drill.

Dave explained that the "new tech" electric drill was the best for the job. It was faster, more accurate, and provided a cleaner finished hole. At the same time, he still uses a very old, very heavy hand plane for final work on much of his wood. With the hand tool he can feel effects from the grain of the wood that he simply loses when using the electric equivalent.

Some of the new tools are so much better than the old ones that they are the only reasonable choice. Some are so much faster, but otherwise no better, that they are probably worth having but not a requirement. And some of the traditional tools are still valuable and best suited to their task.

[Bycrick]

For Paul L, I always wrote a paper log entry once an hour when I was making passages. That was as much to stay awake or make sure the crew had been awake as anything else. The interval is less important beyond having some idea of where you might be if the electronics decide to go south. I’d do a plot every few hours for the psychological reinforcement that I was actually moving since the scenery was the same. I did noon plots for the tradition of computing a day's run.

[CassidyNZ]

Originally Posted by Jim Cate

All this worry about what if a lightning strike, solar flare, atomic explosion or civic upheaval takes out the GPS nav system on your boat... and how much safer the good ole celestial methods are.

Bull puckey!

Jim

Absolutely. The most important reason why I own a paper chart of the South Pacific is so that I can record the voyages I have done for posterity. But I plot them when I get to my destination or home.

At the end of each watch, I record the GPS fix in my logbook so that in the extremely unlikely event that something causes all 5 of my GPS devices to fail, I can navigate by DR from my last known position on the chart that I coincidentally have on board. At the same time I log a waypoint on the GPS device to save me from having to refer to the logbook when plotting the course for posterity. But depending on a paper chart? Not anymore.

When at sea (navigation) the position provided by electronic means is far more accurate than any traditional method can provide and, frankly, I don’t care how good the traditional navigator is, he/she can’t get even close to 5 metre accuracy. In addition things like distance to course make planning en-route so easy, why would anyone want to do this on paper.

FWIW, when I sail say, to Fiji from NZ, I have one thing on my route planning. The waypoint at my landfall in Fiji. I know that my rhumb line will take me well clear of any obstacles (e.g. Minerva) and the distance from rumb line tells me if there is any danger of that obstacle becoming a problem. What else do I need to know?

When not at sea (pilotage) I depend on waypoints that account for inaccuracies (don’t try navigating 50 metres from a rock) and my best ever pilotage device - my eyes.

I get that there are folks that can’t let go of traditional methods but seriously? Millions of people are transported all over the globe every minute of every day using nothing but electronics. Boeing 737 Maxes fall out of the sky because they’re travelling at 600kn in a three-dimensional world when things go wrong. I’m travelling at one hundredth of that speed in a two dimensional world. The two cannot be logically compared.

[Paul L]

Originally Posted by Bycrick

Catching up on some of the posts that I missed.

I’m not speaking of the catastrophic loss of GPS systems or nuclear war. Solar flares might be bad, but they’re rare enough not to trouble my sleep. Lightning strikes more probable, I've had two in my years cruising. But I’ll point out that there have been "hidden" problems with GPS. Bad clocks in the satellites. Or the boat GPS using WAAS, that quietly failed when the Air Force changed the satellite IDs and some GPS receivers didn’t recognize the new IDs and quietly dropped back to not using WAAS but with degraded accuracy. Several people ran aground in narrow channels. Most GPS choose the "best" satellites and use them to develop a fix. But I read several years ago about some new receivers for more critical that we’re supposed to generate ALL the fixes available and then compare them, giving a warning if they didn’t match well enough.

Variation does change slowly, but in my example if you haven’t updated your plotter or GPS unit since you bought it, do you know if the conversion from true to magnetic is accurate? If it was off by 5 degrees when you set your AP, that might be important.


We all know that the electronic chart data is neither complete nor completely accurate. Neither is paper chart data, but we're more conditioned to accept data "on the computer" as being less worthy of skepticism.

My point is not that one should be afraid of electronic systems, but that one has to know how to use them and hopefully have enough situational awareness to know when they might me wrong. If you simply buy it, install it and tell it where you want to go, you might be disappointed where you end up.

I'm not seeing your autopilot setting example with incorrect variation as any issue. There are a number of reasons why you might not get at what you are pointed at when you set a compass course in an AP or for that matter when you tell a helmsmen what compass course to sail. Fortunately with GPS and a chartplotter you have a virtually continuous fix plotted and can easily monitor any course error. Variation does not affect a fix that is not derived from a magnetic bearing.

As far as being more conditioned to accept electronic data on a computer as being less worthy of skepticism, perhaps that's true. But I remember an awful lot of issues occuring because people believed the dead reckoned position or the perceived accuracy of a fix or the accuracy of the plot on a paper chart in the days when no electronics was a available.

[RichMac]

What happens if it fails? Redundancy is important for safe navigation.

In the old days, we only had one of everything, chart, calculator, log transducer, sextant etc. Most importantly, only one navigator, who could get tired, sick and make mistakes.

On our yacht, we have 8 devices capable of navigating, and everybody on board can use them. We are much safer now, but we still need to know the tricks and traps of digital navigation.

[Packman]

The most current information is safest.

[RaymondR]

It's no contest.

Lolling about in the cockpit with an occasional glance at the electronic chart scrolling it's way under the little boaty thing is far better than all that dashing up and down from cockpit to chart table, sharpening pencils (if you can find one among all the clutter of screw drivers, light bulbs, spare fuses etc) correcting compass bearings, consulting tables etc.

[ramblinrod]

Art of Problem Solving 101, Day 1, Lesson 1.

"Any solution mankind can develop to solve a problem, necessarily creates at least one more problem."

There are pros and cons to every possible solution or decision.

Paper charts? They can get wet, catch fire, be blown away, get soiled, be wrong, be non-updated, detract attention from electronic navigation, consume valuable storage space, be difficult to acquire, provide a fixed level of resolution, etc., etc., etc.

Electronic charts? Can fail, be wrong, be non-updated, detract attention from shipboard paper chart navigation, hide information depending on zoom level, etc., etc., etc.

Some say, it is best to use all sources of information to make an informed decision.

What if by attempting to consult all information sources your attention is distracted from other more important ship board duties?

What if there is a conflict; which to use?

What if both or all are wrong?

Anyone who knows anything about boating, should realize that the entire thread is a total waste of server space.

The real answer is, "There is no better solution than what one does that gets them back to port safely"...

…except for those attempting to use a fragile, vulnerable, mobile device, as their primary cockpit navigation instrument. ;-)

[thomm225]

It's much easier these days though to just download the charts you need from OpenCPN to your laptop. (and tablet or phone for backup)

This along with your GPS (and sextant as backup and compasses) you should be in pretty good shape along with the knowledge of a few cardinal points that you can get from the stars alone or those in various constellations

It still used to be exciting though when you didn't have any of these and were searching hard for an inlet and you saw that first white shape coming out marking it!

So the answer is to use whatever is available along with your experience.

[Dsanduril]

At least with the current state of technology the "primary cockpit navigation instrument" should be the fragile, vulnerable, mobile human brain. The use of anything else leads to things like the boat that piled up on the breakwater in front of me because their head was in the marine chartplotter in the cockpit that wasn't zoomed in sufficiently to show the breakwater.

[Pizzazz]

One more thought on why digital navigation is safer than paper navigation. With digital navigation, because so many of the steps are automated and the information can be presented in much cleaner form (i.e. only the relevant information), the chance of making an error is much smaller (way smaller) than with paper navigation. So, it is safer by a wide margin.

Some will say, but how about this specific event, where the chart was not zoomed correctly or a lightning stuck, etc. These are what is called negative outcomes. It is human nature that we add a lot more weight to negative outcomes than positive outcomes. Some of it is due to fear, some of it is embedded in how the human brain is wired. People will remember the time when their handheld GPS ran out of battery power for years to come but will not remind themselves every day how lucky we are to come to the marina safely, with minimum amounts of effort, due to the simplicity and easy of use of the GPS with fresh batteries. Another way to understand this is that people are very unhappy when they lose $100, but only slightly happy when they win $100.

Smarter people recognize this and adjust their behavior. Paranoid people are willing to put up with a lot of unnecessary effort to minimize the chance of a negative outcome. For example, the ship's log. Modern chart plotters will save this information on a memory card, every minute if you want to, with wind, depth, speed data, you can copy it, print it, send it to friends or allow real time tracking for racing events. Yet, some people enjoy plotting it on a paper chart. Nothing wrong with this. But it is not safer, more accurate or more convenient. It is just what we are used to.

Therefore, for people just starting with sailing or who are open to modern technology advances, you will be infinitely better to understand the new technology, the benefits, the pitfalls, failure modes, etc. vs. wasting time on paper charts. If you have an interest in history, then spend your time accordingly but do not kid yourself or others that it is safer.

Just my view,
SV Pizzazz

[Paul L]

Originally Posted by Pizzazz

One more thought on why digital navigation is safer than paper navigation. With digital navigation, because so many of the steps are automated and the information can be presented in much cleaner form (i.e. only the relevant information), the chance of making an error is much smaller (way smaller) than with paper navigation. So, it is safer by a wide margin.

Some will say, but how about this specific event, where the chart was not zoomed correctly or a lightning stuck, etc. These are what is called negative outcomes. It is human nature that we add a lot more weight to negative outcomes than positive outcomes. Some of it is due to fear, some of it is embedded in how the human brain is wired. People will remember the time when their handheld GPS ran out of battery power for years to come but will not remind themselves every day how lucky we are to come to the marina safely, with minimum amounts of effort, due to the simplicity and easy of use of the GPS with fresh batteries. Another way to understand this is that people are very unhappy when they lose $100, but only slightly happy when they win $100.

Smarter people recognize this and adjust their behavior. Paranoid people are willing to put up with a lot of unnecessary effort to minimize the chance of a negative outcome. For example, the ship's log. Modern chart plotters will save this information on a memory card, every minute if you want to, with wind, depth, speed data, you can copy it, print it, send it to friends or allow real time tracking for racing events. Yet, some people enjoy plotting it on a paper chart. Nothing wrong with this. But it is not safer, more accurate or more convenient. It is just what we are used to.

Therefore, for people just starting with sailing or who are open to modern technology advances, you will be infinitely better to understand the new technology, the benefits, the pitfalls, failure modes, etc. vs. wasting time on paper charts. If you have an interest in history, then spend your time accordingly but do not kid yourself or others that it is safer.

Just my view,
SV Pizzazz

I was reading along and agreeing all the way till you pooh poohed keeping a log. We cruise in areas that are unfamiliar to us and some have excessive lightning. Having a log entry that has lat long fix available after a strike just makes sense to me. We are not compulsive, but at least an entry on watch change. A log is also a legal document uf the need arises.
Saving a position on an SD card does nothing for a lightning strike backup.