The Merit of Paper Chart Back-Ups

[svHyLyte]

For those of you that debate the need of paper charts in this GPS Enabled Age, we have just returned from a two week cruise along Florida's southwest coast (see http://www.cruisersforum.com/forums/...s-14448-2.html ). Our primary navigation device is a Garmin 2006C chartplotter that has worked faultlessly for 6 years. Never-the less we maintain a paper plot which is updated hourly or whenever we make a course change.

As it occers, 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 do have several back-up GPS devices and quickly shifted to an older GPSMap 162 connected to our lap-top running nRoute, had we not, and had we not kept our paper plot, we would have been in poop city negotiating our way from 20 miles north of Smith Shoal light to Key West. (Although we did have our trusty Sextant and tables and could have shot a morning round of stars for a fix had that been necessary.)

A word to the wise--FWIW!

s/v HyLyte

[MarkJ]

I agree. We always have a large scale paper chart of the wide area we are working in plus a waypoint and danger point list on the computer (hard copy would be better).
However there is no way I am buying the full chart package for an area. Not at $30 to $40 per chart!

Multiple redundancy in plotters / gps units is No1 priority. I have all my waypoints on 2 GPS units, one hand held battery operated and near new.

Is 6 years life expectancy for a plotter in the cockpit at sea? Its a good life then that its given you


Mark

[Nauticatarcher]

I agree with Mark J, we run two plotting systems, PC with Maxsea and plotter with C-Map NT+, on a passage we put a fix on paper chart (wide area) and keep a log of COG, SOG,Compass, weather, current, We also print off Maxsea a folio of A4 size chartlets of any harbours we might want to get into if we have system meltdown and just throw them away at completion of each leg

[eyschulman]

It's a no brain er- don't go anywhere without real charts and its a good idea to double check your nav. instruments against the charts. I and I am sure many others have had instrument failure- if you are checking against charts you are not badly inconvenienced.

[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.

[waterworldly]

ANother paper chart advantage: hand written notes on the chart itself. Nice when you come back to use/view them at a later date.

[ssullivan]

The space shuttle has 3 redundant navigation computers.

Good enough for international freighters, good enough for cruise ships, cargo ships and megayachts - good enough for me.

(but secretly, I *prefer* paper charts aesthetically - computerized charting is just more practical)

And if the GPS goes out? You still have chart, just not a position calculated automatically for you. You might have to break out the DR skills.

[GordMay]

Originally Posted by ssullivan

The space shuttle has 3 redundant navigation computers...

A Space Shuttle is hardly a practical exemplar of how cruising sailboats can and should implement electronic navigation.

The US Space Shuttle is the most reliable space launcher available. The exceptionally low failure rate of the Space Shuttle is achieved with a combination of determined engineering, and lots of money.
The Space Shuttle Endeavour, the orbiter built to replace the Space Shuttle Challenger, cost approximately $1.7 billion.
Each Shuttle mission costs over $0.5 billion to launch.

Notwithstanding, with a catastrophic failure rate of 1 disaster for every 57 flights, 40% of the Shuttle fleet has been “lost” (Challenger and Columbia).

According to IBM, the early Space Shuttle Orbiters had FIVE computers aboard.
IBM Archives: IBM and the Space Shuttle

"... Five IBM computers — four of which were arranged in a redundant configuration, with a fifth computer acting as a backup unit — allowed early Shuttle missions to continue even if multiple failures were experienced. The computers cross-checked each other more than 500 times a second. In flight, the Shuttle orbiter was controlled by electrical signals generated by the digital computers — a concept called fly-by-wire — and sent to hydraulic-driven actuators.
Each computer consisted of a central processor (IBM's Advanced System/4 Pi - since replaced with the AP-101S) and an input/output processor..."

See also:
The Space Shuttle Avionics System
SP-504: Space Shuttle Avionics System

[MarkJ]

I just don't like living in the past. In 10 years or so there won't be any paper charts.




Mark

[Southern Star]

I'm with Sean - I have two chart plotters (a Garmin 2006C and a 3006C) as well as a handheld GPS and I carry paper charts. Large scale of course, but also enough small scale to enable me to make safe landfalls if the need arises. It is not only comforting, it is still quite cheap in comparison to the potential loss of your vessel, or even the deductible on hull damage under many policies.

Alan, it strikes me that that the caution on digital charts is there solely to protect the manufacturer from liability. If you were relying exclusively upon digital charts and ran aground, then unless the digital chart was the problem (and the error was not reflected on the paper charts), then I can't see how your insurer could refuse coverage. Surely even if there were an express exclusionary clause in your policy, then (unless you made misrepresentations in order to get insurance) there would have to be some causal connection between the chart and the accident.

Brad

[Amgine]

US NOAA charts are created primarily for commercial shipping purposes. They are not created for leisure sailors. As such, the areas of interest to commercial shipping are covered in fine detail and reasonably maintained for their purpose. (Commercial fishing complains about this constantly.)

Paper editions of these charts may very well go away if the US government determines that no commercial need is served, for example by requiring all commercial craft to have a certain level of electronic charting and redundancy. As I understand it the primary reason they have not done so already is that no current commercial grade instrumentation has proven its power security.

But paper charts will not go away in the foreseeable future. Only the US paper charts may go. For example, Canada continues to chart the uncharted regions of their coastal waters where the primary waterway usage is pleasure craft, indicating that non-commercial use is a priority of their bureaucracy. British publication of US paper charts would likely continue apace, while their own chart systems would continue as well. Australia and New Zealand each have their own justifications for publishing paper charts, and I'm fairly confident their primary purpose is not solely commercial consumption but rather the safety of their hyper-obsessed nautical communities.

Not every government or community in the world makes all decisions solely on the economics of the moment.

[Zephyr's Aura]

OK I have a question. All of my sailing has been costal to this point. The charts are readily available and I always carry a paper chart. I was looking on line and there are a number of charts available for ocean crossings. What is the best scale? Are hazard areas clearly marked? Dose a large scale chart show enough detail to keep you off of reefs and sandbars etc? Is there a good place online to view some of these charts?

I use SeaClear as my nav software. Are there raster charts available for ocean crossings? Where do I find them?

Thanks,

Tim

[GordMay]

Originally Posted by Zephyr's Aura

OK I have a question. All of my sailing has been costal to this point. The charts are readily available and I always carry a paper chart. I was looking on line and there are a number of charts available for ocean crossings. What is the best scale? Are hazard areas clearly marked? Dose a large scale chart show enough detail to keep you off of reefs and sandbars etc? Is there a good place online to view some of these charts...

Most ocean passages don’t present fixed hazards; excepting Islands & Continents; which by definition are surrounded by “coastal” waters.

[speedoo]

Originally Posted by Zephyr's Aura

OK I have a question. All of my sailing has been costal to this point. The charts are readily available and I always carry a paper chart. I was looking on line and there are a number of charts available for ocean crossings. What is the best scale? Are hazard areas clearly marked? Dose a large scale chart show enough detail to keep you off of reefs and sandbars etc? Is there a good place online to view some of these charts?

I use SeaClear as my nav software. Are there raster charts available for ocean crossings? Where do I find them?

Thanks,

Tim

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.

[Vasco]

Might be showing my age but we used to use plotting sheets when crossing oceans. Of course we used to have to take sights.