- Do you prefer Vector or raster? Raster has details, vector can zoom-as-you
like........ but misses details....
- What are considered the best S57 maps? I'm interested in mediterranean
area
- Are dedicated mapping systems (Garmin, Reymarine, Navionics) superior, in
terms of map-details and features, to PC based systems?
- Are PC based products (Ozi, Maptech, Rose Point) reliable for autopilot
navigation?

Your thoughts

"Atlas" wrote in message
...
- Do you prefer Vector or raster? Raster has details, vector can
zoom-as-you like........ but misses details....
- What are considered the best S57 maps? I'm interested in mediterranean
area
- Are dedicated mapping systems (Garmin, Reymarine, Navionics) superior,
in terms of map-details and features, to PC based systems?
- Are PC based products (Ozi, Maptech, Rose Point) reliable for autopilot
navigation?

Your thoughts


Why nobody answered? Stupid questions?

"Atlas" wrote in
:


"Atlas" wrote in message
...
- Do you prefer Vector or raster? Raster has details, vector can
zoom-as-you like........ but misses details....
- What are considered the best S57 maps? I'm interested in
mediterranean area
- Are dedicated mapping systems (Garmin, Reymarine, Navionics)
superior, in terms of map-details and features, to PC based systems?
- Are PC based products (Ozi, Maptech, Rose Point) reliable for
autopilot navigation?

Your thoughts


Why nobody answered? Stupid questions?




If you were to seach the archives of this group via groups.google.com, you
will find this discussed in great detail in many threads.


-- Geoff
www.GeoffSchultz.org

Atlas wrote:
"Atlas" wrote in message
...
- Do you prefer Vector or raster? Raster has details, vector can
zoom-as-you like........ but misses details....
- What are considered the best S57 maps? I'm interested in mediterranean
area
- Are dedicated mapping systems (Garmin, Reymarine, Navionics) superior,
in terms of map-details and features, to PC based systems?
- Are PC based products (Ozi, Maptech, Rose Point) reliable for autopilot
navigation?

Your thoughts


Why nobody answered? Stupid questions?


No, not stupid questions. I didn't reply because I don't have any
experience with charts for the Mediterranean area.

But for U.S. waters, I like the S-57 vector charts when zoomed out and
the raster charts when zoomed in close for the reasons you state. The
primary difference to me is that I like the way contour variations and
navaid symbols are presented on the raster charts better than the vector
and I like to see those details that way when zoomed in.

When out on the water I use Garmin BlueCharts on a handheld (GPSMAP
76Cx) as my primary navigation aid. Those charts are not S-57 vector
charts but either raster charts that have been vectorized or based on
the raster charts.

The Garmin BlueCharts are licensed from Navionics are arguably the best
presentation for use on electronic displays. They are fully zoomable
and the detail presentation (like the way navaids are shown) is more
like the raster charts than the somewhat mysterious and not as easy to
discern and differentiate symbols used on the S-57 charts.

I did not find a web site that offers comparison images of all the
current types of electronic charts. This page is dated but gives you a
feel for the differences in the visual presentation of raster and the
various proprietary vector charts brands:

http://www.bluewaterweb.com/Electron...mparePlans.asp

The bottom image, "Transas and Passport" is very similar to the
presentation used on the newer Garmin BlueCharts and current Navionics
E-Chart products. The shadings are varied with the soundings and the
details are everything as would be seen on raster charts.

In using the BlueChart/Navionics charts, the user can choose the symbols
set to be used for displaying navaids from a list of several styles
(NOAA, International, Garmin).

I do seasonal deliveries of motor yachts and nearly all of them are
equipped with Raymarine, NorthStar, or Furuno chart plotters and use the
Navionics electronic charting.

A few of the older NorthStar systems (961 and 962 series?) have what is
essentially a marine grade PC with only the older C-Map BSB (raster)
charts on them. Those are not nearly as good in use as are the newer
systems like the Raymarine "c" and "e" series and the NorthStar 963.

I consider the good marine chart plotters (what you call dedicated
mapping systems) to be much better in use than a PC. Those are
ruggedized and waterproofed for the conditions of use, the displays are
bright enough for use in sunlight and will also dim down for use at
night. On a larger boat a PC would be more useful at the navigation
table but at the helm, I'd want a good marine chart plotter with
something like the Navionics vector charts on it.

In a perfect world, the PC at the nav station can send route and
waypoint data to the chart plotter at the the helm and everything is in
synch on navigation details.

The boats I deliver, although well equipped, do not have the routes and
waypoints I want to use stored on them. So my 76Cx handheld is my
primary point to point or leg to leg reference for navigation. When in
harbors and zoomed in on the handheld for the details, I also like
having the chart plotter for the bigger or zoomed out picture.

I don't use any of the softwares you asked about on a PC on the water to
drive an autopilot so I can't offer an opinion as to how well those
work. I'd think that as long as Coastal Explorer or Ozi or any of them
was providing a constant and reliable source of NMEA data (the course to
steer basically) to an autopilot, they would work fine.

The quality of the autopilot in use is going to be more in the hardware
and firmware in the autopilot itself than in the NMEA CTS data source.

My thoughts? On a larger boat, with a considerable investment, and the
goal of having a good time while doing things safely and well, a good
dedicated mapping system is the only way to go in my opinion. You can
have the other bits and pieces around it (PCs, etc.) and sharing data
and providing inputs. But in the end if only one piece of it is working
it needs to be something that is likely to survive and still be useful
to the end.

And at the end? You are back to a chart or chart book, a compass, your
knowledge of where you think you are or hope you are, and you are back
where all of this started.

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)

I did not find a web site that offers comparison images of all the current
types of electronic charts. This page is dated but gives you a feel for
the differences in the visual presentation of raster and the various
proprietary vector charts brands:

Great link. It looks like there's a lot of details there in those
vectors.... I've found some S57 med maps and I had a go just to "try before
you buy" and the detail is zero!!! Storing vector data is nothing difficult
nowadays, and computational power is fair enough to recalculate and redraw a
chart. The maps you've pointed out show exactly that it is possible to store
enough data into vector based products like if they were rasters.

I'll try to download some of thos NOAA S57 maps to get an idea.

Thanks for your precious thoughts

Atlas wrote:
snip
Great link. It looks like there's a lot of details there in those
vectors.... I've found some S57 med maps and I had a go just to "try before
you buy" and the detail is zero!!! Storing vector data is nothing difficult
nowadays, and computational power is fair enough to recalculate and redraw a
chart. The maps you've pointed out show exactly that it is possible to store
enough data into vector based products like if they were rasters.

On the U.S. S-57 charts I think all the same details are there, at least
on the water anyway, on both the vector and raster charts. On the
adjacent land areas the prominent features that a boater might use are
there too (towers, smokestacks, etc.). But there is little or no detail
of streets, topography, and the like.

And the presentation of the details in the navigable water areas on the
S-57 charts has very subtle shadings in the way it depicts markings for
everything from navaids to piers,pilings, awash rocks, and the other
stuff. When I look at a NOAA BSB4 raster chart (or the Navionics
charts) the details sort of leap out at me in comparison.

It may be that I am an old dog and not doing well with new tricks, but I
really prefer looking at the details on the BSB4 raster over the the
S-57 vector charts. I hope the raster charts are not discontinued any
time in the near future, I'll miss them.

I'll try to download some of thos NOAA S57 maps to get an idea.

Thanks for your precious thoughts

You're welcome of course. Here are two charts (and the starting point
for download links) that are good examples to show you the difference
between a NOAA BSB4 and NOAA S-57 chart for the inner harbor area of
Portland, Maine, USA.

S-57 VECTOR:
US5ME10M - PORTLAND HARBOR AND VICINITY, ME - 1:20,000

http://nauticalcharts.noaa.gov/mcd/enc/index.htm

BSB4 RASTER:
13292 - PORTLAND HARBOR AND VICINITY, ME - 1:20,000

http://nauticalcharts.noaa.gov/mcd/Raster/index.htm

If you can download those through Coastal Explorer it is a little
simpler than using the NOAA map server links above. If the map server
seems unnecessarily complicated, bear in mind that it is part of a
government bureaucracy. And free. :)

NOAA uses the term ENC (Electronic Navigation Chart) for referring to
the S-57 series charts most of the time. The S-57 charts arose from the
IHO international agreement and all the participating nations agreed to
the format, details, etc., and are all supposed to be working towards
producing those charts.

Jack

On the U.S. S-57 charts I think all the same details are there, at least
on the water anyway, on both the vector and raster charts.

(CUT)

I've downloaded the whole NOOA pack, and "flew" to San Francisco and New
York.

When zooming-in, the charts show much greater detail then the med maps I've
seen. Plenty of detail here, fair enough to say bye-bye to raster, at least
for the "offshore" side; for the inshore, yes, raster maps still rule, but
with such a detail, you can easily approach a port allready knowing what to
expect.

Great work done by NOAA.

Maybe someone did the same work for med, who knows.

Jack Erbes wrote:
And the presentation of the details in the navigable water areas on the
S-57 charts has very subtle shadings in the way it depicts markings for
everything from navaids to piers,pilings, awash rocks, and the other
stuff. When I look at a NOAA BSB4 raster chart (or the Navionics
charts) the details sort of leap out at me in comparison.

The entire idea of a vector chart is that it does NOT contain any data
that says how to depict markings such as navaids, unlike a raster chart.
For any navaid it just contains it's type, (geographical) position,
size, height etc. How this is represented is up to the software package
that you use to view the chart.

I've set up my US software package (Nobeltec) such that the vector
charts look like the paper charts that I am used to. This gives me the
'familiarity' that you are looking for as well; wherever I am and
whatever the original source of the charts (UKHO, German, French,
Norwegian). In fact this is much appreciated as on a 3 week trip it's
easy to be in four different countries over here, each with subtly
different paper charts.

I can imagine that you might hate my setup, and would wanna switch to
whatever you are used to. A good software package lets you do that...

Kees

Kees Verruijt wrote:
snip
The entire idea of a vector chart is that it does NOT contain any data
that says how to depict markings such as navaids, unlike a raster chart.
For any navaid it just contains it's type, (geographical) position,
size, height etc. How this is represented is up to the software package
that you use to view the chart.

Thanks for explaining that, I had no idea that the the attributes and
properties of the symbols could be managed like that. But it certainly
makes sense. I'm using the trial version of Coastal Explorer (same
software as Maptech's Chart Navigator Pro) as that is the only software
I have that will use the NOAA ENC/S-57 charts.

The Coastal Explorer help says that the S-57 display in Coastal Explorer
has "complete support for S-57 ENCs drawn according to the S-52
specification". So I guess that is what defines I am seeing? Or is it
the S-52 spec that allows you to further further change the
presentation? Coastal Explorer does not offer any further changes to
what I am seeing.

snip
I can imagine that you might hate my setup, and would wanna switch to
whatever you are used to. A good software package lets you do that...

I doubt that I would not like it, I am very fond of consistency. :)

Jack

--
Jack Erbes in Ellsworth, Maine, USA - jackerbes at adelphia dot net
(also receiving email at jacker at midmaine.com)