The Merit of Paper Chart Back-Ups

[Zephyr's Aura]

Originally Posted by speedoo

These days, the only use for "ocean charts" is if you want to see the bottom contour and water depth. You really don't need them for any other purpose, IMO. As far as navigation and routing are concerned, that can be done by lat and longitude waypoints and some math, or a simple GPS.

If you are crossing the Atlantic to say the Canaries, just get your Canaries charts out when your navigating tells you you are within a few 100 miles.

I would think that it would be prudent to keep a paper chart and plot your position along the way if for nothing else just to have a DR point if you were to loose your electronic navigation. It would also seem to be a handy thing to have in order to plot weather that you might receive on the radio.

Just a thought from the inexperienced...

[Therapy]

Originally Posted by Alan Wheeler

Another slant to the comments. If you run aground while navigating with electronic charts, you most likely will not be insured. There is a warning at start up of all electronic nav units that state that they should not be used for navigation and reference to paper charts should be carried out.

I seem to remember that paper charts have the same sort of warning.

They are an aid to navigation only.

They cannot be relied on to be accurate either.

Money paid, chances taken.

[GreatKetch]

Originally Posted by Therapy

I seem to remember that paper charts have the same sort of warning.

They are an aid to navigation only.

They cannot be relied on to be accurate either.

Money paid, chances taken.

Paper charts issued by the US government have NO such warning. They ARE intended for use in navigation.

The idea of crossing an ocean relying 100% on the reliability of my electrical system to keep my electronic charting system going strikes me as the very height of head-in-the-sand thinking. The normal cruising boat is one lightening strike away from no electronics at all.

[Ex-Calif]

I have been navigating with GPS since about 1999 - admittedly in aircraft - 150 hours a year for 9 years and never had a GPS failure or loss of satellite in flight.

That's 1350 hours at an average speed of about 120kts = 162,000 nautical miles of trouble free GPS navigation. And I have to believe the GPS system is getting better, not worse.

I am really curious for those on the board to provide similar reliability statistics -

Number of miles of cruising under GPS navigation vs. actual need to resort to DR or star shots.

I think most people make a tempest in a teapot when it comes to paper vs. GPS.

There are things way more likely to kill you in the ocean than a failed GPS - like weather and sea state.

[Alan Wheeler]

Alan, it strikes me that that the caution on digital charts is there solely to protect the manufacturer from liability.

Yes it certainly is. But if it's an insurance company, and a possible loop hole exists, I wouldn't want to bet on them not squirming out.

[Steve Pope]

all digital charts are taken from paper charts in the first instance.

[MidLandOne]

The warning is not on official digital charts, just the non official ones (well certainly not the ones I've seen).

Furthermore the US and NZ official digital charts are free (well small charge at the moment for the whole portfolio of NZ ones - around USD45 for the lot as supplied on CD, but will be down loadable from 1 July 2008).

Not much thats good comes free .

[Steve Kidson]

While undertaking studies in Navigation for a commercial qualification, we were taught (and reinforced many times over) that paper charts should be your primary source, electronic devices secondary.

I concur with Wheels that most (if not all) insurance companies will decline a claim if it cannot be demonstrated that paper charts were not being used for navigation.

Major ocean races require all competing yachts to carry a nominated set of paper charts for the course of the race, with particular reference to larger scale charts for ports of refuge. The last Sydney to Hobart race required a set of some approx 50 charts.

Most experienced competitors will have these as a matter of course.

Relying solely on electronic means could (and probably has previously) ended in disaster. How many of you have never had a problem with your PC, Windows, internet, e.mail, mobile phone etc etc.

My 2c worth.

Fair winds

Steve

[MidLandOne]

Originally Posted by Steve Kidson

I concur with Wheels that most (if not all) insurance companies will decline a claim if it cannot be demonstrated that paper charts were not being used for navigation.

I have never heard of that being the case, and would be surprised if it were so, but I have heard of an odd instance of SOLAS vessels having insurance difficulties because of not navigating with official electronic charts (as they are required to use approved charts).

I would be most surprised if there was any difficulty with having ones insurance company respond to a claim if using official electronic charts because, as I think another may have said, the raster ones are exactly the same as the paper ones. The vector ENC's while obviously not copies of the paper ones are approved for navigation of SOLAS vessels and a simultaneous paper plot is not required on them.

In the case, as on a small vessel, where loss of electronic navigation may have a single point of failure I personally do not see any need to maintain a plot on a paper chart as well as the electronic one. A simple method if concerned what a failure could lead to (say during poor visibility of charted features or during an offshore passage) is to just note ones position and relevant data needed to recover navigation manually on a pad. The frequency might be every so many minutes if very close to dangers and visibility at risk or might be once or twice a day if on an ocean passage.

In the end some enjoy maintaining a plot on paper and fair enough.

[Ex-Calif]

Originally Posted by Steve Kidson

we were taught (and reinforced many times over) that paper charts should be your primary source, electronic devices secondary.

And once upon a time airplanes had skylights to take star shots and the horse was the primary form of transportation.

New fangled stuff requires new fangled thinking.

PS - I would love to see evidence that insurance companies denied claims due to the navigation source used.

The big difference between paper and plastic is that the plastic box overlays position on the chart. There are a few ways cause the overlaid position to be in error including using the wrong datum.

[Steve Pope]

I recently bought a set of the NZ charts on CD but couldn't use them on my Mac, the people at Boat Books made no mention of them becoming available (free?) on line. Do you know if the downloadable version going to be in both msdos and Mac formats?

[svHyLyte]

Dan--

The reason I began this thread was the failure of our Garmin 2006C chart-plotter. I merely intended to point out the merit of having back-up Paper Charts. To reiterate:

...after the second day out we began to have periods when our GPS indicated "Lost Satellite Reception". These outages were intermittent and lasted anywhere from a few seconds to a few minutes but occured with greater frequency over the days. Finally, after 3-4 days, the GPS quite entirely simply indicating "Searching for Antenna".

While we did have back-up GPS units aboard--several in fact--absent a chart to plot our highly accurate positions on, the back-up GPS data would have been nearly useless, particularly so if we'd needed to find a harbor of refuge. With our draft, in Florida waters I am not about to go blundering into a pass, or anywhere near shore for that matter, without having a chart to log my positions on and figure my next move. (As for the accuracy of GPS, even WAAS enabled or corrected with differential, I have more than one GPS track log that indicates we were ashore for more than a mile when we exited Big Pass in Sarasota).

As I said earlier--different ships. different long-splices.

s/v HyLyte

[MidLandOne]

Steve - to use official charts you have to have, I'm just assuming this is the problem, a charting system on a computer capable of reading them, the charts themselves are not sensitive to the operating system. There are quite a number of those charting systems around but I suspect none for the Mac's operating system (but I have not had any need to ascertain that).

The one I use is Endeavour Navigator from HSA Systems Ltd in Australia (they have an office in Upper Hutt here in NZ as well). A Google will get them and if you want to talk to them I have found them helpful both here in Upper Hutt and in Australia. It may run on MAC's with the ability to run Windows applications but I don't know that (and see my comment on its user interface which may be a complication for Macs doing Windows).

It is not everyones cup of tea though I would expect because it is aimed at small commercial vessels so has no "attractive gimmicks" - it just does nav for navigators. It also creates its own user interface over Windows (but you can run and use other Windows applications concurrently) which may not be attractive to non commercial users. It is also much, much cheaper than the ones marketed more to the pleasure market such as EuroNav, etc. from memory around NZD500-600.

There is a manual for it on their web site that gives an idea of what is needed to run official charts including licencing, keys, etc (the NZ licence is issued free) if you need that information. Also, on the LINZ site there is a list somewhere (I think in the pdf file describing their raster charts) of charting systems that will run the charts (all do US, UK, Australian as well, of course).

Not promoting the HSA one as best or anything but just as an example which can be referred to and their people readily available on the phone here.

As I understand it the current electronic raster NZ catalogue (which includes all of the small scale charts for the whole of the Pacific and the Pacific Islands NZ supports) will be available for download off the LINZ site from 1 July. Also, LINZ has been running a project producing vector ENC's and my understanding is the first of these will be available later this year, in the first place for the Auckland and Wellington regions. I do not know how they will be distributed but hopefully free to download.

John

[David_Old_Jersey]

I am a paper chart person (with GPS for ease of use)....one day I will even buy a chartplotter! Only used them on other people's boats. But I like 'em cos' they are seductive! But would run a paper chart as well, just not so much

But as far as I am aware every half tide rock and possible tidal stream / height combination has not been accurately recorded to the nearest half inch or .001 of a knot (even if "calculated") for the simple reason that a lot (most?) of the original survey data used was not to this accuracy. Digitising it does not make it more accurate, simply more useable.

The problem I perceive with electronic charts is that they suggest an accuracy and a certainty which is not always the case....with pen and paper no one navigates to the "accuracy" that a Chartplotter allows - which is all fine (and can be a major safety feature) when things are going as planned or the real world difference with the chart plotter does not matter...... but IMO prudent to bear in mind the area you are cruising and the reliability of the source data and what if yer lost the chartplotter for any reason?......not only to get into an anchorage etc - but how to get out!

Not to say one should not use them or even rely on them 99.99% of the time, but.......

[MidLandOne]

In general I agree with you but in my view it is not a problem of electronic charts themselves that may suggest an accuracy and certainly which is not always the case. It is the software that displays them - mainly I suspect a problem with the small pleasure market type chart plotters (but with which I have had little experience of).

For example, the electronic charting system I use allows zooming but with two provisos - it presents a "compilation scale" view which one can always click back to as a check, and if one zooms in much beyond that into improper up scaling it automatically forces one into a larger scale chart - if a larger scale chart is not available it presents you with a grey screen in the chart area instead forcing one to click back to compilation scale or zoom out a bit. While this doesn't work absolutely perfectly it is very good and at least keeps one alert to the dangers.

Originally Posted by David_Old_Jersey

I am a paper chart person (with GPS for ease of use)....one day I will even buy a chartplotter! Only used them on other people's boats. But I like 'em cos' they are seductive! But would run a paper chart as well, just not so much

But as far as I am aware every half tide rock and possible tidal stream / height combination has not been accurately recorded to the nearest half inch or .001 of a knot (even if "calculated") for the simple reason that a lot (most?) of the original survey data used was not to this accuracy. Digitising it does not make it more accurate, simply more useable.

The problem I perceive with electronic charts is that they suggest an accuracy and a certainty which is not always the case....with pen and paper no one navigates to the "accuracy" that a Chartplotter allows - which is all fine (and can be a major safety feature) when things are going as planned or the real world difference with the chart plotter does not matter...... but IMO prudent to bear in mind the area you are cruising and the reliability of the source data and what if yer lost the chartplotter for any reason?......not only to get into an anchorage etc - but how to get out!

Not to say one should not use them or even rely on them 99.99% of the time, but.......