On Sep 26, 10:56 pm, cavelamb himself wrote:
A few months back, Navquest offered free downloads of coastal charts.
I wanted to cover teh Gulf of Texas, and the area up around the
Columbia River entrance.

I couldn't get them from my home computer for some reason.
But the local library computers worked fine.

I copyed off the entire Gulf Coast, the Left Coast, and some of the Right.

I don't think you can still download them for free, but I have themif
anybody really gets going on this.

They are still free...NavQuest is now call Clicktoboat.com

Jere,
Effectively, what you want to do is create a Wiki"depth"pedia and with that,
have the same problem any Wiki solution has, no verification. An outdated,
verified chart has infinitely more value than an uncertified chart. However,
your concern has merit, but your solution doesn't without verification.
Ultimately, the skipper owns the problem and the tool of choice with today's
technology is the side scanning, phased array sonar. With that, he has the
ability to perform his own verification. It works, it's affordable and
ultimately cheaper than the Braille method.
Steve

"Jere Lull" wrote in message
news:2008092615455816807-jerelull@maccom...
I was considering the march of technology and the computing power many of
us have on our boats, then considered the byzantine methods the various
mapping agencies use to create our nautical charts and how out-of-date they
really are.

Has anyone seen a project to collect position and depth data automatically
and periodically upload the data to a central server? I vaguely recall
someone who mapped one or more anchorages automatically like that, and
there's another project where large and commercial ships sample and
analyze the waters they're passing through.

I would love to participate, in exchange for charts that accurately show
what's ahead of our keel.

Yeah, yeah, it's a project that would in some way require the cooperation
of the various national agencies ... Or one of the map sellers might be
interested, as it would give them an incredible edge over the other
suppliers.

--
Jere Lull
Xan-à-Deux -- Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

"Jere Lull" wrote in message
news:2008092615455816807-jerelull@maccom...
I was considering the march of technology and the computing power many of
us have on our boats, then considered the byzantine methods the various
mapping agencies use to create our nautical charts and how out-of-date they
really are.

Has anyone seen a project to collect position and depth data automatically
and periodically upload the data to a central server? I vaguely recall
someone who mapped one or more anchorages automatically like that, and
there's another project where large and commercial ships sample and
analyze the waters they're passing through.

I would love to participate, in exchange for charts that accurately show
what's ahead of our keel.

Yeah, yeah, it's a project that would in some way require the cooperation
of the various national agencies ... Or one of the map sellers might be
interested, as it would give them an incredible edge over the other
suppliers.

On 2008-09-28 05:03:19 -0400, "Steve Lusardi" said:

Jere,
Effectively, what you want to do is create a Wiki"depth"pedia and with that,
have the same problem any Wiki solution has, no verification. An outdated,
verified chart has infinitely more value than an uncertified chart. However,
your concern has merit, but your solution doesn't without verification.
Ultimately, the skipper owns the problem and the tool of choice with today's
technology is the side scanning, phased array sonar. With that, he has the
ability to perform his own verification. It works, it's affordable and
ultimately cheaper than the Braille method.
Steve

Not at all. Many would collect datums, a central server would collate
and "prove" the data. Verifying data reliability is not that tough a
job. In fact, it's pretty easy if you have enough data to work with.

Side-scanning sonar is okay, but itself limited.

And Wiki has been compared by professionals against the best
encyclopedias, and uniformly been found to be at least as accurate as
the best. Its peer review at its best.

--
Jere Lull
Xan-à-Deux -- Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

On Sat, 27 Sep 2008 21:13:09 GMT, Jere Lull wrote:

On 2008-09-27 15:03:37 -0400, "Steve Lusardi" said:

Solve the problem by investing in a phased array, side scanning sonar. They
are very affordable and reliable. See the Interphase 180.

Not needed. I don't mind finding a channel by the braille method.


I've heard that about your area. A guy moved up here a few years ago,
and was SHOCKED at having to know about all the rocks. He said people
run aground all the time in the Chesepeke, and it's just mud. He said
he learned that he really has to be on his toes up here, and know
where all the hazards are, including the uncharted ones... I never
noticed that I had to be "extra" careful, because I've always sailed
here.

On 2008-09-28 08:45:04 -0400, said:

On Sat, 27 Sep 2008 21:13:09 GMT, Jere Lull wrote:

On 2008-09-27 15:03:37 -0400, "Steve Lusardi" said:

Solve the problem by investing in a phased array, side scanning sonar. They
are very affordable and reliable. See the Interphase 180.

Not needed. I don't mind finding a channel by the braille method.


I've heard that about your area. A guy moved up here a few years ago,
and was SHOCKED at having to know about all the rocks. He said people
run aground all the time in the Chesepeke, and it's just mud. He said
he learned that he really has to be on his toes up here, and know
where all the hazards are, including the uncharted ones... I never
noticed that I had to be "extra" careful, because I've always sailed
here.

Yup, we're certainly worlds apart.

If I see a constant 9', we have no real care. Except for the channels
we cross, we typically see 12' in the main Bay up here.

If I depended only upon what's on the existing charts, the distance to
the next anchorage south (Swan Creek with what used to be Swan point in
between) would at least double. For quite a distance at low low tide,
the depth shows about 6 feet as I cut close to the way point I put
where the fish trap used to be. Cut that corner by 50' and we bump.

Now if I could get reliable information on the bottom north of that, I
might be able to cut a mile or two off our trip as I believe that fish
trap was on a 'lump'. A forward-looking sonar wouldn't do the trick for
us. Given reliable information that an unmarked passage exists I'll
search it out while dropping GPS bread crumbs, perhaps even spend some
time determining how wide or narrow the passageway is. Improved sonar
would help that, but I usually glance at the depth and speed only
momentarily while sailing. A graphical screen would be a distraction
almost all of the time.

--
Jere Lull
Xan-à-Deux -- Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/

"Jere Lull" wrote in message
news:2008092704581416807-jerelull@maccom...
On 2008-09-27 04:18:32 -0400, "Dennis Pogson"
said:

"Jere Lull" wrote in message
news:2008092615455816807-jerelull@maccom...

Has anyone seen a project to collect position and depth data
automatically and periodically upload the data to a central server? I
vaguely recall someone who mapped one or more anchorages automatically
like that, and there's another project where large and commercial ships
sample and analyze the waters they're passing through.

I would love to participate, in exchange for charts that accurately show
what's ahead of our keel.

There is a program called Ozidepths which works in collaboration with
OziExplorer, the best of all navigation software.

You could Google for it, and as Oziexplorer has programmable factilities,
you might be able to adapt Ozidepths to suit your purpose.

Sadly, OziExplorer doesn't support Mac, so I couldn't participate.

Friends don't let friends do Windoze.

--
Jere Lull
Xan-à-Deux -- Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/


That's a pity, but if the project was considered all that important, buying
a cheap Windows laptop wouldn't stop me.

Dennis.

On 2008-09-29 03:42:06 -0400, "Dennis Pogson"
said:

"Jere Lull" wrote in message
news:2008092704581416807-jerelull@maccom...

Sadly, OziExplorer doesn't support Mac, so I couldn't participate.

Friends don't let friends do Windoze.

That's a pity, but if the project was considered all that important,
buying a cheap Windows laptop wouldn't stop me.

Remember, Mac laptops *can* run windoze -- in fact are amongst the best
for running Vista -- I just won't.

I have to endure MicroS..T at work. At home, I just want a machine that
works without the "fiddling". (I'm a programmer, primarily working in
MS products. I too often have to repair/rebuild the machine due to what
I consider light duties.)

--
Jere Lull
Xan-à-Deux -- Tanzer 28 #4 out of Tolchester, MD
Xan's pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI trips & tips: http://homepage.mac.com/jerelull/BVI/