Traditional or digital navigation - which is safer?

[RaymondR]

One of the advantages of digital charts is that the systemic errors ie those caused by various geoid models being used will eventually be corrected out provided of course that we can ever get world wide agreement on which to use.

The instruction manual I received with my Magellan hand held had a listing about two or three pages long on the corrections needed for countries around the world to bring the GPS coordinates into compliance with their printed charts.

[chrisr]

relevant to this discussion is that many ships these days have switched to fully electronic navigation, and no longer carry paper charts

these systems are quite a bit more sophisticated than small craft systems, have multiple redundancy and rely on on-line internet connection for chart updates. the systems must be approved by class.

i have worked with these systems and they are a big improvement over paper - even when you are drawing > 15m and > 225m LOA. it is only a matter of time before the technology filters down to pleasure craft.

don't fight technology...embrace it !

cheers,

[Jim Cate]

That doesn’t keep me from visiting the islands, it just means that I’m not using the electronic toys to tell me what’s happening.

Well, if you had the now elderly Interphase Probe forward scanning sonar that we have

(an "electronic toy" by your definition) you could have seen that pinnacle from around 100 feet away and avoided it.

Bloody toys... they're everywhere, ruining good sailors lives. Bt handy, none the less.

Jim

[Bycrick]

I hate to disillusion you. I’ve had an Interphase Forward looking soñar since 2000. It didn’t show the pinnacle well even when I knew where it was. Knowing it was there, I could sort-of see it. But I’d never have recognized it otherwise. I’ve found it sometimes helpful, but certainly not worth what they wanted for it. When it finally quits, I’m going to get a 50khz unit with better deep water performance, or take a look at what’s new then to see if forward looking technology has improved. I’ve got a lot the "electronic toys." I was in that business for years. But I no longer treat the electronics as a hobby. I use them, but I don’t implicitly trust them.

[Benz]

Originally Posted by jtsailjt

I’m actually not missing that the rocks are plotted in the wrong place, I just realize that it’s the same misplotted chart whether it’s displayed on paper or digitally on a screen. You are assuming (and we all know where that leads) that those of us who prefer our charts to be displayed digitally aren’t ‘looking out the window’ just as you say you do and instead are just blindly driving the little boat on our chart plotter without paying any attention to the fact that the reefs aren’t located as depicted in areas where we know the chart and geoid are misaligned. Even in areas where they aren’t misaligned, I’m always double checking to confirm that what I see on the screen matches what I see around me by visual cues and/or radar or by bottom contours. Whether you prefer paper charts or digital ones, it’s always wise to be skeptical about any single source of info and you seem to get that but I wonder why you seem to assume that those of us who prefer digital charts don’t.

The thread is about whether digital nav is safer than non-digital. After all this, you've finally admitted that digital alone can't cut it, and you need to back it up by 'visual cues.' So we're on the same page, except that I prefer to plot compass bearings on paper (can that even be done with a screen? If so, can it be done in less time than with a ruler?).

[conachair]

Originally Posted by Benz

So we're on the same page, except that I prefer to plot compass bearings on paper (can that even be done with a screen? If so, can it be done in less time than with a ruler?).

Very quick in opencpn, just create some routes, just need to reverse the bearing if you're making a line from a point instead of to a point. Though after that you there's a reverse route menu option. View over sat image charts or nautical charts. No mess on the paper charts and zoom in/out as much as you want.
Very quick to get NLT & NMT bearings as well.

If it's better/worse than paper is probably much more to do with personal opinion based on what you're used to/how you learned in the first place than actual 'better or worse'.

Miles better IMHO

[RaymondR]

I am fairly certain that the electronics in my chart plotter is less liable to transposition errors than I am.

[jtsailjt]

Originally Posted by Benz

The thread is about whether digital nav is safer than non-digital. After all this, you've finally admitted that digital alone can't cut it, and you need to back it up by 'visual cues.' So we're on the same page, except that I prefer to plot compass bearings on paper (can that even be done with a screen? If so, can it be done in less time than with a ruler?).

I didn’t “finally admit” that we all need to back up whatever navigation methods we choose with using whatever other inputs are available such as visual cues, I’ve always thought that was obvious. I’m surprised that you ever thought otherwise. I think we have differing definitions of digital vs traditional navigation. You seem to think that what I consider to be such common sense things as using visual cues to back up whatever your instruments or computations or DR plot tells you is the exclusive domain of the traditional navigator but I think it applies equally to both those who like paper charts and those who prefer a digital display. After many years of using paper charts I didn’t suddenly turn off my brain when I started using a chart plotter, and I didn’t stop constantly comparing where my plotter (or my DR) tells me I should be with what I’m seeing outside. Just because someone prefers a chartplotter to paper charts doesn’t mean he ignores all other inputs. Yes, like the automobile driver who drives off the unfinished end of a bridge because his GPS tells him to, I’m sure there are some boaters who have the same lack of situational awareness at sea. But I have a feeling that most of them probably don’t belong on the water (or with a drivers license) at all and it’s not the type of navigations fault that did them in. I still have some old paper maps kicking around in my car and think they can be useful to ‘zoom out’ and see the big picture of where I’m trying to get. But, like about 99% of motorists, when traveling in unfamiliar areas I rely mostly on either the cars nav package or google maps or Waze on my cellphone. Sure there are pitfalls to be avoided but if you’re smart enough to figure out the pitfalls involved in ‘traditional nav’ you’re also smart enough to use the necessary judgment required to effectively use digital navigation tools such as chartplotters.

[easysailor123]

using both is probably the safest option. If we already have the option of relying on digital navigation, why not? I always say the holistic approach is the best approach. Speaking about "digital tools", last few days I spent at boot Dusseldorf and came across something quite interesting. There is an app launching this summer,called Bayfinder, that tells you sailing options based on your current position, sailing conditions and your points of interest. Since I usually sail in foreign waters, this seems like something to keep an eye on. What do you think? Would you say our sailing culture is ready to embrace these kinda technologies? Are you? here is more info
https://www.bayfinder.app/

[Jim Cate]

I hate to disillusion you. I’ve had an Interphase Forward looking soñar since 2000. It didn’t show the pinnacle well even when I knew where it was. Knowing it was there, I could sort-of see it. But I’d never have recognized it otherwise. I’ve found it sometimes helpful, but certainly not worth what they wanted for it.

I was not aware that I needed disillusioning, being that I have been using the Probe since 1996. I believe you when you say yours did not show the pinnacle , for we don't know what sort of target that specific hazard made... you were there and I wasn't and some objects just don't reflect the sonar pulses very well.

But we find the Probe to be very useful when in poorly charted waters, especially when the water is murky or when it is dark. Entering new to us anchorages is made far less traumatic by it's (admittedly imperfect) abilities to see ahead of the boat. And the Probe has shown us hazards that were otherwise invisible to us, saving us a grounding or two.

And unlike you, I found it good enough value that when I changed boats in 2003 I immediately purchased a new one. I feel naked without it!

I see adverts now with fantastically detailed sonograms of the bottom in various directions, but I'm not hearing reviews that support the claims... and the prices are even more offscale than Interphase's were. I await further developments with hope but little confidence t hat an improved instrument will emerge.

The display on our now ~17 year old Probe is slowly fading, so I wish they'd hurry up! Meanwhile, we kinda trust but always try to verify by other means, eyeballs and experience mostly.

Jim

[Bycrick]

Your post said that if I’d had a Probe, I’d have seen the pinnacle. I do have one, am familiar with the operation of it, and I couldn’t see the rock on the Probe until I knew where it was. So it didn’t solve my problem.

I didn’t say that the Probe didn’t work. It does. But in shallow water, it’s forward view is limited to 4-5 times the depth. Given a flat sandy bottom peppered with large solid rocks, you’ll get a fair amount of backscatter which shows up as a broad band of potential targets. Recognizing which ones are real and which are artifacts of the system is an imperfect art.

The basic limits are set by the 200khz operating frequency and the limited number of elements in the transducer array. The combination of those means limited resolution. I’d love to have a forward looking sonar that would reliably see 100’ ahead. The side-looking higher frequency sonars are astoundingly good in shallow water, so one would think that the technology is available.

On the other hand, I’ve found places where a 50khz system that reliably reads deeper water would have saved me from getting close enough to shallow water to have to worry. Esmeraldas, Ecuador and Golfo Dulce, Costa Rica both come quickly to mind.

As I’ve said before, I love the new toys. But they won’t solve all of your problems, won’t work well for you if you don’t understand how they work and their inherent limitations. And when they suddenly decide not to work correctly, for whatever reason, you need to know enough to recognize that they’re wrong and be able to do something reasonable without them.

[Mailman]

Interesting discussion again, but as many have said, there will be no conclusion, just opinions. As this has been drawing my attention many times, I also want to share my perspective:

- Yes, having both is a safe option, but as many have said: If you don't know how to use the paper charts, there is no use. Or the other way around: using digital properly, requires paper chart knowledge. Why doesn'tit work the other way around?
- If you're not sure your paper knowledge will last or you've never learned using paper charts, I recommend you to have 2 digital systems at your disposal.
- Navigation is a broad term. For instance: I use Navionics for navigation purposes, but find the Moorspots app to be usefull when entering marinas and anchorages, as it gives a lot more information and opinions than a pilot book. I would not buy pilot books, but use apps like Moorspots. So it depends on how broad your definition of navigation is.

So, what is my setup?: I use 2 digital navigation systems. My iPad and my iPhone (as a backup), both with Navionics and Moorspots. Besides this, I have some old charts for in case, but no pilot books. Not because I cannot use paper charts, but because I fear that I'm not able to keep the right level of paper charts navigation skills. I'd rather grab my backup device, instead of using paper again. In emergency situations I'll manage with the paper charts.

[Happ]

Originally Posted by RichMac

I started navigating with paper charts and celestial, there was no choice then.
Watch "Yacht Navigation - how to be safe", https://youtu.be/iTQxLhp45lg

I really like the accuracy and ease of modern digital navigation, but many people still prefer the old traditional methods. Do some sailors still navigate with safety using just paper chart plotting and a sextant?
Or have we all switched off our navigation brains, and been seduced by the convenience of GPS?

The answer is simple. Paper charts by the government will cease being printed in the next few years.

[bassman1956]

There's no way I'll ever trust electronic nav entirely. So on my slow course of becoming a better sailor, I am learning manual / traditional methods first.

[Hasbeen]

I spent 55 hours in 1976 lying ahull in the Solomon sea, riding out the edge of a cyclone. It was rough & unpleasant, but the main problem was no sun, so I had no idea of where I was, how fast I was traveling if at all, or what leeway I was making.


To add insult to injury, there was no sun for the next 2 days, before the sky cleared, so I had to sit & wait for it.


God how I wished for sat nav, but in those days a sat nav system cost more than my boat.