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  #11  
Old 12-12-2012
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Re: Gps navigation advise

If you can do chart plotting on paper then the GPS is easy. Most books on navigation cover GPS, but don't go into great detail. This is because it all depends on the model GPS you are using. Most GPS's will come with instructions on their use. For the most part it is very intuitive, most people who have lived in the modern electronic world should have no problem picking one up and using it. If I could sum up what most of the books have to say about GPS it would be this, always check you route, when you put in a route to a waypoint into the GPS the machine doesn't check for obstructions between you and the waypoint. You need to do this yourself.
I use a Garmin 76 handheld and it works great. There very good at showing you where you are and whats in the immediate area. There weakness is in planning and showing you the big picture. To much scrolling and zooming in and out. Paper charts are much better at showing you the big picture at a glance.
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Old 12-12-2012
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Re: Gps navigation advise

John,

Nothing to do with MY setup - it's merely a function of the input data, which is wholely supplied by governmental agencies - not the private sector. To MY knowledge, there is no private sector surveying of the world's waterways being conducted - it's just cost prohibitive. Consequently, everyone using GPS, computer based charts, and paper charts, are by and large relying on information generated by USGS over the past century.

Granted, some of this is up to date, so to speak, early 2000 data, but there's an enormous amount of information that is older than many of the forum members. John, if you have the opportunity to traverse the ICW in South Carolina, Georgia, etc..., you will quickly discover what many travelers of this waterway have. Charts, regardless of where they're generated from, are by and large, quite inaccurate. It's not the fault of the electronic gear, it's the input data.

Cheers,

Gary
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Re: Gps navigation advise

Just to add to my last post. I normally have the hand held in the cockpit with me and rely on it to give me my position. But you had better believe I have a paper chart right there next to it. I could waste a good five minutes messing around with the Garmin trying to get the big picture, when a paper chart combined with what I see on the GPS will tell me what I need to know in secounds.
I should also state that I'm only talking about the handhelds. A full sized electonic chartplotter may not have this problem.
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Re: Gps navigation advise

Yes, the full-size plotters are far more user friendly when it comes to zooming in and out. Just takes a few seconds.

I also was a radioman in the Navy, as well as the ship's diver (tough job). Updated chart information came in almost daily, and when you looked at the paper charts in the nav room they were a maze of scribbled information over the original document. Nearly all of the scribbles, though, related to the ocean and approaches to harbors.

Gary

Cheers,

Gary
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Re: Gps navigation advise

Quote:
Originally Posted by chucklesR View Post
Quote:
Originally Posted by JonEisberg
How are your electronic charts more accurate than the properly-updated government paper equivalent they are based upon?
Simple answer Jon - I update my chips monthly with a simple download that takes 5 minutes. How often do you update paper?

As a radioman in the navy I tracked the thousands of hydrolants (messages to up date charts) and watched the quartermasters (navigators) doing the updates. I have no intention of doing that, and most sailors don't either.
Of course, you are correct - your e-charts are far more likely to be updated with changes to nav aids, etc., than paper charts, I was still fixated on the overall notion of the accuracy of the surveys upon which e-charts are based which Gary had raised in his post...

Whenever this discussion of e-charts vs paper is raised, I feel compelled to link to Nigel Calder's most excellent take on the inherent danger of digitizing paper charts, and the risks of over-zooming... Here's a link to a previous post of mine on the subject:

Does anyhbody still navigate?

Hmmm, I wonder if Nigel Calder will become the latest inductee to join Don Street in Mark's Pantheon of Famous Nautical Fools? (grin)
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Re: Gps navigation advise

Quote:
Originally Posted by MarkofSeaLife View Post

I don't have paper charts on this boat and would never sail with anyone that uses them. They are unsafe and obsolete.

Mark
I'm surprised to hear you've had so little luck fishing during your passages - you're certainly pretty adept at trolling on the internet... (grin)

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Quote:
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I can therefore assume that you won't be sailing with the US Navy, the British RN or other major Navies/Shipping lines anytime soon.

Gerry
They all use electronics.

AIS has seen to that. It's illegal for them to operate without AIS so it means it is illegal for them to operate without electronic charts.
I'll bet the US Coast Guard is pretty annoyed with that requirement that they be transmitting AIS continuously - must make a lot of their drug interdiction efforts, for instance, considerably less effective...

Funny that the US Navy seems to turn off their AIS transponders off whenever they see me coming, perhaps as a Tall Ship delivery skipper, I might pose some sort of unique threat... My efforts to deal with a small carrier conducting their spring time maneuvers off Camp Lejeune one night last year might have been eased had they been running AIS at the time... But, I suppose they must always have it turned on in a hotter spot like the Gulf of Hormuz, right?
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Re: Gps navigation advise

Quote:
Originally Posted by MarkofSeaLife View Post
They all use electronics.

AIS has seen to that. It's illegal for them to operate without AIS so it means it is illegal for them to operate without electronic charts.
1. They all use electronic AND paper charts.
2. Re. Navies and Coastguard vessels; "illegal for them to operate without AIS", NO! Nor is it illegal for them to operate without navigation lights etc. You do realize that AIS can be displayed on a range of screens that do NOT have a charting capability.

As I said originally I could care less if you navigate your own boat using an ouija board. Experienced sailors (and you are one) need to be careful when dispensing advice to newbies. Stating that paper charts are "unsafe and obsolete" and that you "would never sail with anyone that uses them" implies that Electronic charts ARE "safe and up to date". This is patently NOT the case. ALL charts are just aids to navigation and should be read with caution.

As I tell students and anyone who will listen, remember the golden rule of navigation; L. T. F. W.









Lookout The Fu@&ing Window.
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Re: Gps navigation advise

For those that believe in the infallibilty of GPS charts and charting. These two photos were taken from my helm within seconds of each other. I have dozens of such shots.
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Last edited by boatpoker; 12-12-2012 at 01:43 PM. Reason: spelling
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Re: Gps navigation advise

Quote:
Originally Posted by travlineasy View Post
John,

Nothing to do with MY setup - it's merely a function of the input data, which is wholely supplied by governmental agencies - not the private sector. To MY knowledge, there is no private sector surveying of the world's waterways being conducted - it's just cost prohibitive. Consequently, everyone using GPS, computer based charts, and paper charts, are by and large relying on information generated by USGS over the past century.

Granted, some of this is up to date, so to speak, early 2000 data, but there's an enormous amount of information that is older than many of the forum members. John, if you have the opportunity to traverse the ICW in South Carolina, Georgia, etc..., you will quickly discover what many travelers of this waterway have. Charts, regardless of where they're generated from, are by and large, quite inaccurate. It's not the fault of the electronic gear, it's the input data.

Cheers,

Gary
I understand what you're saying, and yes - I have had the opportunity to traverse the ICW thru SC, GA, etc... More than once, as a matter of fact (grin)...

I would disagree with you, in that in general, I find most of the charting to be incredibly accurate... Shoaling inlets are the obvious exception, of course, and anywhere else where the tidal ranges are larger, and the current runs strong... On Sunday morning, entering Port Royal Sound from outside from the north, I cut the corner by about 4 miles inside the sea buoy, shooting the narrow gap between the extensive shoals to the north of the very long entrance channel... As usual, I was astonished how accurate the charting of such a dynamic area remains, it was right on the money...

But again, I have to wonder what sort of e-charts or programming you're using, because in my experience, I've never seen any of them that have placed me on dry land anywhere along the ICW or its inlets (with the possible exception of a small, extremely changeable one such as Carolina Beach, perhaps) My C-Map for the waters inside Barnegat, for example, are slightly off - but anyone relying solely on e-charts in such a place, at such a scale, is really asking for trouble, anyway...

As gotd 25 suggests, that's when it's time to Look Out the Freakin' Window... (grin)

Last edited by JonEisberg; 12-12-2012 at 02:01 PM.
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Re: Gps navigation advise

My primary navigational tool is, naturally, my eyes, followed by common sense, followed by my GPS/Plotter, and sometimes, I even look at the charts, which I have lots of onboard.

The area just south of Carolina Beach, where the ICW is about 100 feet wide, is where I noticed that there was a 50-foot descrepency. Also just south of Jacksonville Beach, for a distance of about 3 to 5 miles, the same 50-foot difference between the actual position and GPS location.

My Lowrance HDS7 uses Lowrance charts, and also Navionics - I prefer the Lowrance mode, which is incredibly accurate and detailed.

Fire up your GPS/Plotter and take a close look at the ICW behind Virginia's Barrier Islands from Cape Charles to Chincoteague. I think, John, that you'll find it interesting to say the least.

Good Luck,

Gary
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