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Old 03-03-2010, 17:55   #91
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Quote:
Originally Posted by GordMay View Post
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

And on top of that after each "trip" the whole system was overhauled, and tested and replaced if needed. Kind of like the I use this OIL in my racecar you should to. Yea the engines are rebuild after each race how the hell is that the same. But the feel of papercharts is just too much to let go no matter what.
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Old 03-03-2010, 20:06   #92
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Originally Posted by sneuman View Post
Aside from being a prudent "back up", I think you really need to have a paper chart to properly view the big picture. Call it navigational forehandedness, but I like to be thinking a few moves ahead, and in my view the myopic display of a chart plotter (or GPS enabled laptop maps) is a poor substitute for paper. Part of it is the same reason I prefer printing out long articles rather than read them online.
That is how I feel a lot of the time but seeing how younger people "move about" that "myopic display" without a problem makes me realize I am just aging and unable to "keep up" with the new way things "are".

They really can see the larger image even if it is off the screen. I, like you, learned and still need that whole large sheet of paper so I can "see" things properly. Then I need the smaller scale to "see" more stuff, closer stuff.

My son does not need that. He can slide sideways and zoom in and out and it stays organized in his head while I become somewhat disoriented.

I have only read a little about it recently but find that aging is tough and most deny it's effects while still not liking "old people". LOL.
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Old 04-03-2010, 02:17   #93
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"more chance of being struck by lightning" - isn't that how the euphemism (or is it similie) goes? Sure it can happen, but am I the only one to have paper charts rendered unreadable by everything from termites to vomiting crew?

Why is there always so much discussion over the merits or otherwise of paper and electronic charts? The are both the same, they have exactly the same information on them, you can take bearings and plot your position on both. The only difference between a paper chart on the nav table and an electronic one on the chart plotter is the medium in which they are displayed.........well when I say only difference, there is the fact that you can't overlay radar on to a paper chart

or AIS

or get real time tide information

or get acquire and radar target and track on MARPA

and......I'll stop there.

If it's backup your after, buy a handheld
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Old 04-03-2010, 03:35   #94
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The main reason I prepare and use Paper Charts prior to sailing is to provide me with a “Line of Position”, when coasting.

This is used in conjunction with the radar in a technique called “Parallel Indexing” to always provide me or my crew with a safe distance off the shoreline as well as true compass courses and measured distances from highlighted reefs and conspicuous fixed radar targets to keep on that line and out of trouble if for some reason like collision avoidance, I were to deviate.

As the captain, whenever I come on the bridge, I look at the paper chart with the index lines and I look at the distance off the shore at an identifiable target point and I know we are on course since this plan was carefully prepared long before we left the dock.

Just ask yourself one question in this debate.

If the GPS says you are cruising along in safe water and the Radar along with the paper chart says you are steering into danger…..which one would you believe?

Then ask yourselves whether it is worth learning how to use the prepared chart and radar properly and keep that practice alive?

To me GPS is like a calculator or computer... it sure makes things fast and easy, but I still do those sums in my head..
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Old 04-03-2010, 05:22   #95
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I have six GPS's aboard -- three handhelds, two pucks and a fixed Furuno -- and three laptops. I have some experience with lightning, and know of the experiences of others, and am convinced that, faraday cage or not, nothing is safe.

I use paper when I can because my wife and I like it. It is a pleasure to shut the computers off and use a pencil.

Unfortunately, in this part of world, it is quite expensive to buy paper charts as backup and often impossible to find places with large-size copiers if I borrow charts.

Fact is, most cruisers we meet, from around the world, do not bother with paper. Cost and hassle is the main reason.
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Old 04-03-2010, 06:12   #96
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Quote:
Originally Posted by Therapy View Post
That is how I feel a lot of the time but seeing how younger people "move about" that "myopic display" without a problem makes me realize I am just aging and unable to "keep up" with the new way things "are".

They really can see the larger image even if it is off the screen. I, like you, learned and still need that whole large sheet of paper so I can "see" things properly. Then I need the smaller scale to "see" more stuff, closer stuff.

My son does not need that. He can slide sideways and zoom in and out and it stays organized in his head while I become somewhat disoriented.

I have only read a little about it recently but find that aging is tough and most deny it's effects while still not liking "old people". LOL.
I'm sure you're correct, to an extent. But there's a limit to how many "offscreen pages" you can really keep track of in your head. I would be the first to admit that chartplotters are indispensible for navigating a narrow, poorly market channel, for example. But for the bigger stuff, I want to see the whole thing.

Just to be fair, I'd make a point that might even out the argument here. Several years ago, I had the experience of a large breaking wave that stove in a portlight and swamped the nav table with seawater. The paper chart that was laying there became pretty much useless at that point. Of course, the water also zapped a GPS and we had to use a tiny handheld Garmin Gecko that we'd stored in a drybag.

We eventually did manage to get the chart point of being simply damp, and used it, with the Gecko, for the rest of the trip.
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Old 04-03-2010, 06:39   #97
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We too have had GPS 'holes' - but also I like not having to rely on the power draw of the computer for plotting.
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Old 04-03-2010, 08:13   #98
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Quote:
Originally Posted by Pelagic View Post
This is used in conjunction with the radar in a technique called “Parallel Indexing” to always provide me or my crew with a safe distance off the shoreline as well as true compass courses and measured distances from highlighted reefs and conspicuous fixed radar targets to keep on that line and out of trouble if for some reason like collision avoidance, I were to deviate.
That is exactly what I do with electronic charts. I find it puzzling that not everybody knows that electronic charts used in combination with a good electronic chartplotter, can do everything that a paper charts allows you too, plus more.

Someone in this thread stated that he could modify the paper chart with mariner notices, implying that this isn't possible with electronic charts... that simply isn't true because again: you can do everything with an electronics chart plus more.

Quote:
If the GPS says you are cruising along in safe water and the Radar along with the paper chart says you are steering into danger…..which one would you believe?
I would surely hope that all sailors know that both radar and GPS show the truth and it is the charts that are wrong, regardless if they are paper or electronic.

So just for the exercise, let's see how to handle that situation (which comes up all the time where we cruise) for paper chart and for electronic chart;

paper chart: basically, you can switch off your gps. I can only hope that a good heading sensor is connected to the radar so that we can take bearings to land features with it. If not, we can still use it for a quick overview but not for plotting position. It's back to the compass bearings in that case. Hopefully you have a compass in your binoculars or else ... etc. Now, I assume we all know how to plot your position using bearings (radar or compass) on land features. This is the way to handle the situation and we can check it by measuring distance to shore on both chart and radar for confirmation.

electronic chart: we first curse the chart surveyor. we know that our radar is right and we know our GPS position is right. We switch the radar to north-up and drop it's picture over the chart. We curse the surveyor again and next put in the offset so that the chart aligns with the radar image. Done.

Quote:
Then ask yourselves whether it is worth learning how to use the prepared chart and radar properly and keep that practice alive?
Preparing charts before departure (plotting your routes, marking dangers, making yourself familiar with angles/directions to look for closest danger etc.) and knowing how to use radar isn't just something helpful... it's a must. It doesn't matter if you use paper or electronic charts though.

When we sail through an area that is badly surveyed with charts known to be in error, or a clear danger that we must de-tour around, I often intentionally approach that danger until I can positively identify it. After that, I can plot a waypoint for the tack or turn with confidence, plus I mark that danger in the right spot on the chart.
The trouble is when you can't find the danger. May be you just can't find it or may be it's gone (reef taken out by a hurricane, quake or whatever). When this happens we drop the sails and continue very slowly with a watch on both foredeck and aft (controlling steering with AP remote). We do that until we find the next marked danger on the chart or until we are very sure that we cleared all danger and have nothing but open water in front of us. This has happened to us in the Turks & Caicos. We also found a reef there that was over a mile closer to us than the chart showed.

cheers,
Nick.
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Old 04-03-2010, 17:50   #99
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Originally Posted by sneuman View Post
.... there's a limit to how many "offscreen pages" you can really keep track of in your head. I would be the first to admit that chartplotters are indispensible for navigating a narrow, poorly market channel, for example. But for the bigger stuff, I want to see the whole thing.
zoom out

Quote:
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...electronic charts used in combination with a good electronic chartplotter, can do everything that a paper charts allows you too, plus more.
Precisely
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Old 04-03-2010, 20:29   #100
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If i was told i can take One set of paper charts for the area i was cruising in OR One GPS/Plotter for the same area, but not both, i would pick the paper charts in a heartbeat....

Thankfully i don't have to worry about that as i carry both anyhow....

A question for those with chartplotters, how often do you correct your electronic charts ?? if at all that is....

Mine are corrected monthly, the system i use when cruising is this Transas, TransasNavigator.com which is the recreational version of this ECDIS system Transas | Navi-Sailor ECDIS 4000 Multifunction Display which is fitted to the offshore supply vessels i work on.
Now this program is not cheap, i am talking about the rec one here, just the folio of all the charts for the Aussie coastline is A$1730.00!!, and that does not include the Program, GPS or Laptop, so it would be a poor investment for me not to have them corrected....

My point being, if you are using paper charts OR a chart plotter, OR both, and you crack up on a charted navigational hazard that has not been applied to your charts/plotters you could have serious insurance/liability problems, especially if a third party is injured or killed....

I know for a fact this is the case in the commercial sector....

EDIT: by the way i am in no way affiliated with the above companies, for me it is just the best system i have used...
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Old 04-03-2010, 20:40   #101
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Hi IslandHopper,

The charts that are off are in out of the way places, like Turks & Caicos, where the most recent survey was 1784 or something like that. 1st world coastlines are charted so accurately that you can't put a waypoint on a buoy because you will actually hit it.

ciao!
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Old 04-03-2010, 21:24   #102
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Hi Nick how are you,

What i was getting at are the new hazards or features that have been added but not placed on the current available chart, part of my job is putting some of these in place when we are constructing Offshore Platforms and Pipelines and such...

We had an incident four years ago where we where using 20t anchors with 90m of 75mm wire penant and a 5t unlit buoy at the surface, we had ten of these three miles away from the platform. The whole area had a 10nm exclusion zone centered around the platform that was anounced in the BA Notices to Mariners 6 months before the incident.
What happend was a 60ft Yacht (GRP) came sailing through them a 2 in the morning, hitting one and doing some serious damage to the hull and nearly sinking himself, long story short he tried to sue for the damage (not insured) and costs of the salvage, he didn't get a brass razoo and had to cough up for his legal expences as well.
The reason he got nothing was it was found he did not have upto date corrected charts....

If you are interested have a quick look here Australian Hydrographic Service - Notices to Mariners 2010 these Aussie ones come out every two weeks, the BAs are weekly....

Cheers
John
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Old 04-03-2010, 21:39   #103
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Denying that things never fail on a boat is not a wise attitude to take. Denying that you never need two or more sources for cross checking your work is the same. Its that simple.
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Old 04-03-2010, 21:45   #104
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Yes, I've sailed a lot in Western Europe where all the countries send out these notices so often that it is hard to keep up with them. In Rotterdam I know a shop that sells charts that will also update your paper charts for you with all the info from the mariners notices if you don't want to do that yourself. I wonder if they do electronics charts too nowadays or stopped the service.

But I can assure you that in most of the 3rd world waters, there has never been a single notice ever. So it's just you, a chart that is hundreds of years old and reefs everywhere around you. It also means no sailing at night... but I wouldn't even do that there with a good chart.

cheers,
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Old 08-03-2010, 08:31   #105
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"... as old fashioned as it may seem, I wouldn't think of casting our lines without proper paper charts leading our way. This, of course, is for reasons of reliability and redundancy. But also, much like preferring the tactile quality of the printed book to a computer screen, I like the feel of a nautical chart. It takes me back to a world as wide as it once was. It evokes a sense of wonder and an urge to wander that no cold screen can."

http://www.cruisingworld.com/destinations/charted-waters-1000081337.html
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