Chart
Providers
So where do you get all this neat chart data so you can pop it up on
your new cartographic display? There are several possibilities:
Charts on a Chip
Many different chart formats are available on memory cards, which are fast, reasonably
waterproof, and not subject to vibration problems when your boat is pounding toward
Bimini. Offshore charts are provided by Navionics and C-MAP, while inland data can be
supplied by Garmin, C-MAP, and Lowrance. There are many formats. Each
cartridge holds between 6 and 80 charts, and new mini format cartridges (C-card from
C-MAP, micro G-Chart from Garmin, and NavChart from Navionics) may hold several hundred
charts. Prices range from $100 to $400 per cartridge.
Since the data is in vector format,
it does not look like conventional paper charts, although CMAPNT charts look darned close
when viewed on a color display. In color or monochrome, vector charts tend to be simpler
and look less like familiar paper charts than the other electronic chart format, raster
charts. However, they have some substantial advantages over raster charts:
- Very fast screen update rates
combined with greatly reduced storage and processor requirements due to the vector format.
- The ability to change from very large
to small scales while still being able to read text and identify icons and other features
(fonts are constant size).
- Charts are seamlessly integrated so
that you don't run to the edge of a chart and have to pull in entirely new map data.
- Chart information is stored in layers
so that data may be selectively shown or removed from the image, and chart attributes can
be queried for incremental information.
At least two potential problems
exist:
- There are at least ten chart formats
from several vendors which make it next to impossible for a retailer to have the right
chart for your particular device in stock. Chart data is frequently out of date.
- The chart images don't look like
conventional NOAA paper charts.
Downloadable Vector Charts from a
CD-ROM
This is the newest category, and already Garmin, Magellan, and Lowrance have GPS
receivers which can download map data from a CD. You can select the geographic area, and
in many cases, the type of information of greatest interest to you (points of interest,
marine aids to navigation, road networks, hiking trails) until it fills up the memory in
the GPS. Some allow you to download any portion of the CD, while others are on a "pay
per view" basis where you have to pay to unlock each geographic areas. We see great
potential in this storage method.
Raster Charts on CD-ROM
Raster charts are electronic files made by scanning a paper chart. NOAA has teamed up
with a private distributor (Maptech®) to bring their library of 1,000 charts to the
public. The charts are stored on CD-ROMs with high memory storage capacity and tolerance
for wet environments. Each CD-ROM stores up to 50 NOAA charts and inset charts of harbor
areas. The chart images, when viewed on a color LCD or CRT display, look just like the
paper source map. In addition, other national Hydrographic Offices are beginning to use
the same raster format, so that the software is compatible with foreign chart providers.
The current software available for
displaying raster charts is dramatically better than that available even two years ago. It
is easy to use, utilizing most of the common software interfaces that make newer software
operate consistently. Chart re-draw speeds are greatly improved, so that zooming and
panning are not chores. And, obviously, computers are dramatically better each year, with
more speed, better displays, and almost universal inclusion of CD-ROMs in all portable
models.
Software features are rocketing
ahead, as well. Among the more impressive are the new mapping engines, which make raster
charts practically seamless, and make it easier than ever to select the right chart for a
given scale. Another great feature is the integration of tide and current information with
the chart presentations, so you can see where the current will be ebbing or flooding on
the next leg of your voyage.
Regardless of the hardware or charts
you select, we feel that you will thoroughly enjoy navigating with these products, and
will get more enjoyment from your boating, too.