An admiralty chart is a nautical map or chart that is used for navigation purposes for the oceans and seas. The admiralty charts are drafted and distributed by the United Kingdom Hydrographic Office and are protected by Crown Copyright. Currently, there are over 3,000 admiralty charts used, which essentially project the entire globe on different levels of detail. The charts themselves will come in a variety of forms depending on the overall purpose or application for sailing. Admiralty charts will come in different scales so as to allow those sailing the seas or oceans to infer the necessary information for navigation.
Large scale admiralty charts will usually be used to develop approach and entrance strategies into harbors. A medium scale chart is used for navigation in more heavily trafficked areas. Smaller scale admiralty charts are used for generally more open areas. Furthermore, admiralty charts are issued in different series depending on the actual vessels navigating, such as the Small Crafts Series, which provides for even more detail at smaller scales.
An admiralty chart is important for various reasons. It gives important information for every single consideration to navigate the seas safely. Depth, tidal information, land features, coastline, traffic schemes, and seabed composition are just some of the factors included in an admiralty chart. Furthermore, many agencies actually require vessels to have up to date admiralty charts for insurance purposes. If an accident occurs during navigation and admiralty charts on board are not up to date, insurance carriers may consider the policies invalid.
