S57 format is used for nautical charts, especially for ENC electronic chart displays used in shipping. S57 files typically appear in a folder containing multiple files. We import the file set by selecting the .000 file for import. The file type setting in the Import dialog therefore refers to s57 as 000 format.
To import from S57 (000) format:
Choose File-Import from the main menu.
In the Import dialog browse to the location of the files and double-click on the .000 file.
Tables, drawings and a map that combines the layers for display will appear.
Use Style to style the layers and labels as desired.
S57 files normally are automatically imported using the correct projection. This can be verified by showing one of the imported drawings as a layer in a map with a "known good" layer such as Bing or Google streets. If the projection information is wrongly specified, we must launch Assign Initial Coordinate System in the Info pane to specify the correct initial projection for the imported component.
Importing from the NOAA nautical chart in S57 format shown in the import dialog above results in a complex, difficult-to-read display using default formatting.
S57 charts can require a large amount of "tinker time" to style in an appealing format. The usual strategy is to make copies of the tables and drawings and to simplify each in various ways, such as removing points that mark the locations of soundings.
The labels components typically include labels for soundings, that is, depth of water at the indicated location...
... as well as text labels marking town names and other locations.
To verify the S57 chart has been imported with correct projection we can create a Bing streets image server data source and then show the S57 drawing as a layer in a map with the Bing layer. In the above illustration we have used the Style pane to change the fill color of areas in the drawing to transparent so we can see the Bing layer through the drawing layer. We also have changed the point style to 0.75 point dots, and we have set the width of lines and area borders to 0.5 point.
The file obviously has been imported with the correct projection, given how the drawing neatly lines up with the boundaries of islands on the Florida coast.
Soundings labels can often be used exactly as imported, to provide depths of water in a map.
S57 drawings are often an organizational mess. It is common to encounter areas that completely overlay other areas, hiding them below other areas.
In the image above we have made a copy of the main drawing and table created upon import. In the copy to simplify the presentation we have removed all objects except areas, and then we have removed three areas that overlaid most of the drawing. To see the remaining areas, which in many cases overlap and cover each other, we have used transparent color for the fill color, and we have colored the main color (used for area borders) with a unique color from a palette for each different object attribute for the various areas. For greater visibility we used the Layers pane to set the background color to black so the lighter colors used for area borders appear more clearly.
Zooming in to the center of the view we see the typical jumble of objects found in S57 charts.
If we use Style to assign hatch patterns to areas based on the content of the Object field in the drawing's table, we can see that the area objects overlap and cover each other. There is an enormous amount of valuable data in a typical S57 file but we must work hard to use that data and to present it in comprehensible form.
Encrypted S57 - The US and Japan appear to be the only two countries which publish ENC maritime charts in S57 format at no charge. Other countries charge for the data, which has led to widespread unauthorized copying. The response of the ENC industry has been to develop an encrypted form of S57 that requires a special code key to read. The Manifold dataport does not support encrypted S57.
Assign Initial Coordinate System
Example: Import an ESRI ADF File and Apply Style and Hillshading