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Old 20-01-2013, 15:31   #76
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Originally Posted by Kettlewell View Post

For unknown reasons there are many well-documented differences between NOAA ENC and raster charts. One would think they come from the same data, but they are frequently different. Panbo has been discussing this for years. Differences too between various private company electronic charts too.
Respectfully, your quote incorrectly truncated my post.

The reference I was making was to the fact that on paper charts notes such as "Position Approximate" or other annotations regarding positions, etc. are much easier to read on the printed versions of charts.

Bill
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Old 20-01-2013, 19:50   #77
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Re: U.S. Navy ship goes aground due to bad charts

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Originally Posted by svHyLyte View Post
I find it astonishing that the CO of that ship would not have gotten stern anchors out to have prevented this. That is very poor ship handling, at the least, in my view.
It's a 1300 tonne ship - the one anchor fitted weighs 1500 lbs; so they wouldn't be able to hump it back aft.
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Old 20-01-2013, 20:23   #78
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Re: U.S. Navy ship goes aground due to bad charts

Moving close to areas with reefs at night the master needs high confidence in their charts and knowing their actual position on chart relative to all hazards. The radar watch should have been busy constantly confirming position. Reef breaks will show up on good radar. Would also imagine lookouts constantly with IR/night vision lenses as well.

If not high confidence in charts/ or inadequate watchkeeping one would have to question the master being there.
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Old 20-01-2013, 20:26   #79
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Re: U.S. Navy ship goes aground due to bad charts

"For unknown reasons there are many well-documented differences between NOAA ENC and raster charts. One would think they come from the same data, but they are frequently different."
You'd have to know the source data and the different production processes, and then the reason for any differences in the charts would become obvious. For instance, if they both start with the same source data but the vectors MUST be made using interpolation. Simply because vector displays may "create" interpolation at some scales, where a raster chart would simply have blanks.
Even simple paper charts become unreliable if you look for too much precision. The colors are printed out of register, or one plate shifts, as a normal part of the lithographic process. Or the paper is not kept in a temperature and humidity controlled environment, and the size of the sheet literally changes overnight, in between ink printings, if a 4-color press was not used.
Got a paper chart? Has it been folded? Then it stretches, more error. Paper charts are inherently unstable even before the printing starts, and mylar and other stable plastics are used when a reference sheet needs to be maintained.
That's all just the tip of the iceberg. I think "we" all know that a navigator never knows where he is, regardless of how they are navigating. All we know is that we're somewhere, more or less, and what really counts is how large the circle of error is.
Navy on exercises? Who knows what circumstances were imposed on that ship.

Google Earth uses many many sources for data, some less accurate than others. I think that by now they've finally corrected their datum for New York City. Google used to geocode everything in NYC (a fairly well known and highly mapped place) incorrectly, because Google was using the WGS datums with NYC datasets. And as anyone actually based in NYC could have told them, the NYC datum was based on old Dutch New Amsterdam co-ordinates (even in 2004-5) and a special offset had to be used, which Google's amateur cartographers were unaware of.
Cartographers used to encourage field conformation--folks sending back information about errors--and they used to provide new editions of the corrected maps back to the folks who reported errors as a way of saying "thank you!". Electronic mapping? Nope, no one admits they need feedback, no one says thank you, no one admits they are chock full of errors. Especially Google. Then there's the Apple Maps fiasco. I wouldn't expect Bing to be any better, and haven't heard anything about the Microsoft TerraServer in a long time.

USN? Wait a few months for the whitewash to come out.

Lodesman-
A 1500# anchor just needs 30 men to get the load down to 50# each. Or 15 sailors, each shouldering 100#, which is what many footsoldiers carry in their packs these days. got a wimpy crew? No problem, 1500# goes wherever you want it, with one rope and one helicopter, and with fleet maneuvers, there's always a helo around. Of course, an American warship would never be measured in tonnes. That's metric, that's still anathema here.
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Old 20-01-2013, 21:44   #80
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Re: U.S. Navy ship goes aground due to bad charts

EXCUSE ME.

Big Brass Heads are going to roll on this one.

Any USN Ship while Piloting waters in Foreign Sovereign Waters will have the Brass at the Bridge.

This would be especially true if transiting a UNESCO World Heritage site ie; Marine Sanctuary with world significance.

So no it is not going to fall on the shoulders of those below the Brass.

There is more to this Story then any here can speculate.

Lloyd

US Navy apologizes for damaging reef, but still no explanation for foray into Tubbataha - InterAksyon.com
MANILA, Philippines - The commander of the United States' 7th Fleet has apologized for the grounding of the minesweeper USS Guardian on Tubbataha Reef, a protected marine sanctuary in Sulu Sea, but still fell short of explaining why the ship was sailing in the protected and restricted Philippine waters in the first place.
Philippine legislators have called for an investigation into the matter, with senators saying the US - and possibly the Philippine government - must shed light on the nature of the mission that found the Guardian stuck in the reef.
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Old 20-01-2013, 22:48   #81
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Re: U.S. Navy ship goes aground due to bad charts

There are questions being asked by locals about whether the PI CG called the Guardian to question their intrusion into this area.

Senators demand explanation as U.S. Navy says inaccurate data possible cause of Tubbataha grounding - InterAksyon.com

My years in the Navy will back most of what's been said here...CO=toast. Probably others. If neglect is charged, and proven, and the PI govt makes a scene (as they should) it could be more than early retirement.

IMO this is a "No excuse" deal, they were inside a World Heritage zone, near a reef known worldwide! Better for US foreign relations to totally throw the CO under the bus, beg forgiveness (which means buy it) and move on. NOTHING is worse than the biggest, smartest, richest country in the world blaming a bad chart. It's embarrassing. My country and My Navy look pretty dumb right now
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Old 20-01-2013, 23:39   #82
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Re: U.S. Navy ship goes aground due to bad charts

I keep my boat in Puerto Princessa, the nearest port to Tubabataha. I think I can offer up some local knowledge about the charts and the reef.

Was the chart off is the first question. Well, yes, pretty much all charts are off in the Philippines, so it's likely that the chart was off. Very little survey work has been done since the 1940's. The most accurate chart I have for Tubbataha is dated 1938 and corrected to 1949. The NAMIRA charts (Philippine Chart Agency) offer no more information for this area than the original US ones. There are essentially copies. C-MAP edition 2 is useless throughout the Philippines and I know of no one who uses them here.

So, the chart is likely off. My experience of the area would suggest that this would be somewhere in the region of 150m to 200m to the south east. Basically, the original survey was done on Luzon datum, not WGS 84, hence the discrepancy.

The reef itself is probably the best dive site in South East Asia and as such is heavily protected. At the beginning of each season, new mooring lines are attached to the blocks (no anchoring permitted) and their GPS coordinates relayed to the dive boats who have permits to operate there. The reef is very accurately located in this respect.

So how could the US Navy believe the chart was 8 miles off? The only thing I can think of was that they were using the wrong chart. As mentioned CMAP edition 2 is so far off as to be unusable. CMAP Edition 3 on the other hand is fine. Perhaps the Navy was on that particular occasion using the wrong chart. A chart that everyone in the Philippines knows is useless.

Seems to me the US Navy hasn't done its due diligence regarding chart selection in the Philippines.
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Old 21-01-2013, 00:20   #83
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Re: U.S. Navy ship goes aground due to bad charts

Looking at the chart images, I see that there are land areas which would show up on radar. If you have land targets which aren't on your charts, its time to STOP THE BOAT until you figure things out. Whoever was on the bridge will soon only be qualified to drive Carnival Cruise ships.
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Old 21-01-2013, 00:31   #84
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Re: U.S. Navy ship goes aground due to bad charts

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Originally Posted by donradcliffe View Post
Looking at the chart images, I see that there are land areas which would show up on radar. If you have land targets which aren't on your charts, its time to STOP THE BOAT until you figure things out. Whoever was on the bridge will soon only be qualified to drive Carnival Cruise ships.
Definitely.

You have wonder what the watch was doing assuming they monitor radar position and use IR/nite vision lookouts moving at night in coral waters.

Didn't miss.
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Old 21-01-2013, 04:12   #85
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Re: U.S. Navy ship goes aground due to bad charts

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Whoever was on the bridge will soon only be qualified to drive Carnival Cruise ships.
Ouch! That'll leave a mark
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Old 21-01-2013, 06:59   #86
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Re: U.S. Navy ship goes aground due to bad charts

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Originally Posted by bewitched View Post
I keep my boat in Puerto Princessa, the nearest port to Tubabataha. I think I can offer up some local knowledge about the charts and the reef.

Was the chart off is the first question. Well, yes, pretty much all charts are off in the Philippines, so it's likely that the chart was off. Very little survey work has been done since the 1940's. The most accurate chart I have for Tubbataha is dated 1938 and corrected to 1949. The NAMIRA charts (Philippine Chart Agency) offer no more information for this area than the original US ones. There are essentially copies. C-MAP edition 2 is useless throughout the Philippines and I know of no one who uses them here.

So, the chart is likely off. My experience of the area would suggest that this would be somewhere in the region of 150m to 200m to the south east. Basically, the original survey was done on Luzon datum, not WGS 84, hence the discrepancy.

The reef itself is probably the best dive site in South East Asia and as such is heavily protected. At the beginning of each season, new mooring lines are attached to the blocks (no anchoring permitted) and their GPS coordinates relayed to the dive boats who have permits to operate there. The reef is very accurately located in this respect.

So how could the US Navy believe the chart was 8 miles off? The only thing I can think of was that they were using the wrong chart. As mentioned CMAP edition 2 is so far off as to be unusable. CMAP Edition 3 on the other hand is fine. Perhaps the Navy was on that particular occasion using the wrong chart. A chart that everyone in the Philippines knows is useless.

Seems to me the US Navy hasn't done its due diligence regarding chart selection in the Philippines.
Thanks for the input, but I am still baffled.

I gather that you know of no accurately geolocalized paper chart for the area.
Using Luzon datum for WGS84 input would not account for the reported discrepancy. (100 to 200 m vs the reported c. 15 000 m; in a previous post, I also found about 8NM error between a satellite-derived position and several charts)
You state that CMAP ed 3 charts are fine. Now CMap charts are supposed to be perfect copies of official charts. For Cmap (NT+, MAX ...) chips at least, the list of official charts that have been used is readily available on the net. The list should be the same for CMap ed 3 charts (and why CMap ed 2 from 2011 should be wrong (unless the ed 3 is more recent))
e.g. covering that area
C-MAP Chart Catalogue - NT MAX Chartlisting
Now If no official charts are accurate, does that mean that CMap has 'corrected' the official charts using sat pics ?
Could you give us the lat/long of the light at the S end of the southern reef on Cmap ed 3 ?
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Old 21-01-2013, 07:27   #87
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Re: U.S. Navy ship goes aground due to bad charts

As I linked to previously (#65), and others have mentioned, this is a well-known reef. It's regarded as the Phillipines' best reef diving location. It's a UNESCO World Heritage site. The lat/lon for the park, AND the lat/lon of the 10 nm buffer zone are part of the published act creating the park (Tubbataha Reefs National Park Act of 2009).

And, it should have shown up plainly on radar...

Hate to say it, but as a navigational error this is right up there with Costa Concordia. Imagine if it had been a big cruiser or an aircraft carrier....
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Old 21-01-2013, 07:47   #88
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Re: U.S. Navy ship goes aground due to bad charts

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Originally Posted by Lake-Effect View Post
As I linked to previously (#65), and others have mentioned, this is a well-known reef. It's regarded as the Phillipines' best reef diving location. It's a UNESCO World Heritage site. The lat/lon for the park, AND the lat/lon of the 10 nm buffer zone are part of the published act creating the park (Tubbataha Reefs National Park Act of 2009).

And, it should have shown up plainly on radar...

Hate to say it, but as a navigational error this is right up there with Costa Concordia. Imagine if it had been a big cruiser or an aircraft carrier....
Ludicrous...
I have plotted (red crosses) the first 4 lat/long coordinates in the 2009 Act (disregarding the local Datum) They match perfectly the park limits as shown on CM93 charts...
These coordinates are wrong by 8 NM according to sat views (see a previous post of mine)... So the grounding has NOT taken place within the park limits as officially defined.

Don't be too harsh on that poor OOW. The charts he relied on were incredibly far off the mark: 8 NM !!!!
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Old 21-01-2013, 07:57   #89
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Re: U.S. Navy ship goes aground due to bad charts

"Any USN Ship while Piloting waters in Foreign Sovereign Waters will have the Brass at the Bridge."
Brass, as in the folks up the chain of command? An expendable minesweeper ranks above "garbage scow" but is way down the food chain in the USN, you won't find any brass onboard and even the Captain won't count as "brass" in the larger picture.
Further, the Captain won't be on the bridge ALL the time, in any waters. Maybe he was up for 20 hours and grabbing some sack time. Maybe he was esconsed in the head with cramps. Maybe he was just off watch and trusting in his XO. Or maybe, he was dealing with other routine military affairs that yes, required him to leave the bridge or at least leave the chart table. Heck, maybe he in sick bay with acute abdominal pains. We just don't know.

All you can say for sure, is that we don't know what happened there, and we won't know for some time, if at all. How long did it take for the true positions and orders of the vessels involved in the Gulf of Tonkin incident to come out? The USS Pueblo?

Different times, same Navy. Same rules apply.
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Old 21-01-2013, 08:08   #90
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Re: U.S. Navy ship goes aground due to bad charts

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These coordinates are wrong by 8 NM according to sat views (see a previous post of mine)... So the grounding has NOT taken place within the park limits as officially defined.
Even if you are correct that the published coordinates in the legal doc are truly off by 8 nm, there is a 10 nm buffer zone around the whole area that they should have been observing, which would have kept them away by 2 nm.
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