The BSB file format is used for marine charts in the form of raster images. BSB files can be obtained free of charge from a number of sources, including the NOAA, OpenSeaMap, and Antares charts. The format consists of two types of file; The .bsb file contains meta data and documentation about the chart. The .kap file contains the chart image itself. The current version of AngelPilot opens .kap files but not .bsb files, and only supports charts which use the Mercator projection.
A GeoTIFF file is simply a TIFF image file with additional tags which give georeferencing information. It can be opened by any image viewer which supports TIFF files, but the georeferencing tags are often ignored. Marine charts in GeoTIFF format are relatively rare, but Antares charts are supplied in GeoTIFF format as well as BSB format. AnglePilot can open GeoTIFF files which represent Mercator projections, and are orientated north up.
The chart creator function of AngelPilot saves files in .apc format, which is a proprietary format. The data is encrypted and can only be opened using AngelPilot running on the same device that was used to create the .apc file. This arrangement is to prevent satellite images being copied and distributed in contravention of their license.