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-   -   The danger of GPS as the sole means of navigation. (http://www.sailnet.com/forums/seamanship-navigation/102259-danger-gps-sole-means-navigation.html)

jackdale 08-07-2013 06:20 PM

The danger of GPS as the sole means of navigation.
 
The National Geospatial-Intelligence Agency misplaced a reef in the Philippine Islands by eight miles on its digital nautical charts, which helped cause the USS Guardian to run aground Jan. 17, destroying the ship.

NGA director Letitia Long told Chief of Naval Operations Adm. Jonathan Greenert that the digital nautical chart display of the Tubbataha Reef in the Sulu Sea was wrong due to erroneous commercial satellite imagery. Long made the assertion in letters obtained by the watchdog website Government Attic.

That error was compounded by “exclusive reliance” of the USS Guardian crew on GPS as a “single source of navigation.” The crew did not pay heed to lighthouses on the reef, according to a 160-page post-wreck investigation report by Adm. Cecil D. Haney, commander of U.S. Pacific Fleet.

How a Misplaced Reef on a Digital Chart Helped Destroy a Navy Minesweeper - Nextgov.com

The Canadian Coast Guard has this on their chartplotters.

http://www.pbase.com/jackdale/image/135247862.jpg

capttb 08-07-2013 07:29 PM

Re: The danger of GPS as the sole means of navigation.
 
Quote:

The crew did not pay heed to lighthouses on the reef
If they had paid heed to visual ATN's would that be "navigating by seaman's eye" and considered a second means ?

Minnewaska 08-08-2013 06:21 PM

Re: The danger of GPS as the sole means of navigation.
 
Yup, when near the coast, you just have to look up and see ATNs, features, etc are where they say they are. Pretty simple.

The tough part is if there are uncharted obstructions or chart errors and you haven't made the update. It's very possible it would be wrong on paper charts too, however.

aeventyr60 08-08-2013 06:42 PM

Re: The danger of GPS as the sole means of navigation.
 
Quote:

Originally Posted by capttb (Post 1070655)
If they had paid heed to visual ATN's would that be "navigating by seaman's eye" and considered a second means ?

More commonly refered to as piloting, Which takes into account many factors, depth, wind, tide, current, water appearance & color, landmarks, hand bearings, small scale charts, mud maps, written directions, and many times the "pucker factor".

Ninefingers 08-08-2013 06:52 PM

Re: The danger of GPS as the sole means of navigation.
 
My iPhone is a whole lot easier to understand than my chartplotter, which I have given up on.

I would love to know how to use paper charts better, but I don't believe there is any formal teaching in my area.

sailordave 08-08-2013 06:55 PM

Re: The danger of GPS as the sole means of navigation.
 
On my boat I've got Depth, Analog Wind, Speedo (not currently wired up) Handheld GPS, CHARTS and most important, my Mark IV eyeballs.
The small Garmin chartplotter/gps that came w/ the boat wouldn't fire up.
I *may* splurge and get an IPAD for general navigation and planning... but I sure as hell won't rely on it as my primary means.
The way I see it is this: If I do things the "old fashioned" way w/ judicious use of new fangled... I'm less likely to make an error in judgement than if I rely solely on technology.



Which is why I shake my head at people who go out and buy their first boat as a fully equipped 40+ footer and think they are sailors.

SlowButSteady 08-08-2013 07:31 PM

Re: The danger of GPS as the sole means of navigation.
 
Quote:

Originally Posted by Ninefingers (Post 1071201)
My iPhone is a whole lot easier to understand than my chartplotter, which I have given up on.

I would love to know how to use paper charts better, but I don't believe there is any formal teaching in my area.

You might want to start with this little book. It's not perfect, but it ain't bad either.

Capt Len 08-08-2013 09:34 PM

Re: The danger of GPS as the sole means of navigation.
 
Reminds me of a beautiful schooner on the south end of atu taki. they had a radar fix on the north end and didn't look the chart closely.High tech sans common sense will always be costly.

baboon 08-08-2013 09:56 PM

Re: The danger of GPS as the sole means of navigation.
 
Quote:

Originally Posted by Ninefingers (Post 1071201)
My iPhone is a whole lot easier to understand than my chartplotter, which I have given up on.

I would love to know how to use paper charts better, but I don't believe there is any formal teaching in my area.

At the risk of stating the obvious, the data used for your phone is the same used for marine chartplotters. The problem in these cases is usually not an equipment failure, the least expensive handheld GPS is amazing at telling your position on the face of the earth. The problem is the maps themselves.

I am surprised by how much people trust the electronic charts, enough to pilot around a rock with just 20 feet to spare.

Another great source is local knowledge. Guide books, fisheman, crusty old guys at the local marina etc.

RTB 08-08-2013 10:52 PM

Re: The danger of GPS as the sole means of navigation.
 
GPS has been awesome from Texas to George Town, Bahamas, to Brunswick Georgia. Every now and then, something just isn't right however. It becomes clear, and one makes a smart decision to ignore what the chartplotter is showing. This is very rare from what I have seen, though.

Ralph

http://www.sailblogs.com/member/brogdon/


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