This dataset contains point, line and polygon data of the marine environment surrounding the Cocos (Keeling) Islands. It includes coastlines, bathymetric contours, coral outcrops and other features. Coverage extends to the whole of Cocos Keeling Isalnds.

The themes have been grouped so as to increase the ease of use of the data. The individual themes have been grouped into the following shapefiles:

• Infralin.shp - Infrastructure lines
• Boundlin.shp - Boundary lines
• Marinelin.shp - Marine lines
• Surveylin.shp - Survey lines
• Islandlin.shp - Island outlines
• Marineply.shp - Marine polygon
• Islandply.shp - Island polygon
• Boundply.shp - Boundary polygon

Not known prior to GA's receipt of the data (no metadata is available). Data was received as ArcInfo Export files. GA converted the data to Shapefile format. GA projected the data to CKIG92 with a coordinate shift to match the Cadastre (assuming it was received as UTM Zone 47 WGS72).

The multitude of individual shapefiles were checked and those of similar themes were then grouped to provide a smaller set of shapefiles, thus making them more usable.

The North Keeling atoll was translated and warped to more accurately match the orthophotography. The amount of translation and compression required can be found in the Cocos GIS documentation.

Line themes were built into polygons to allow areas to be queried.

Comparison with other datasets indicates that the positional accuracy of this dataset is variable. For West Island features match other datasets accurately. For other islands features may be displaced by up to 30 metres from matching features in other datasets.

The North Keeling atoll was displaced about 130m to the east prior to the adjustment. After the adjustment the displacement (compared to the orthophotography) was less then 2m.