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)