Raster charts: A raster-scanned electronic chart is like an electronic snapshot of a paper chart.
On-screen it looks just like the same familiar paper charts you've used for years. If you're using a color monitor, you'll
usually see the original colors from the paper chart, though SoftChart uses a slightly different color palate. Raster charts
are produced by Maptech and SoftChart in the United States, NDI in Canada, British Admiralty in England and by official hydrographic
offices in a number of other countries. Although raster charts normally run on computers some dedicated plotters that raster
charts. Raster charts are available in geographical groups and are distributed on CD-ROM. They are tried and true technology.
Vector charts: Vector charts are distillations of genuine paper charts, but their presentation is different.
Vector charts can have virtually the same information as their raster equivalents. Until recently, vector charts were usually
displayed on dedicated plotters with monochrome displays, but today more manufacturers are making plotters with color displays
and much improved feature sets. The most popular vector charts (for plotters) in the world are made by C-Map and Navionics,
and they come on proprietary cartridges.
Vector charts are also now available for computer-based electronic charting systems. Nobeltec, Transas Marine and MaxSea
are all programs that use vector charts. Vector displays can allow you to view all or select "layers" of information to reduce
clutter or add detail to your chart. And the depth soundings and other information are always very readable - no matter the
scale or rotation of your chart. There are many other advantages. We like vector cartography and we and think you will too!
Which is best? Chart publishers argue about whether vector charts are better than raster charts or vice
versa when running on a computer. We feel that each type has its advantages, and either type can serve you very well. |