Abstract
The NOAA Electronic Navigational Charts (NOAA ENCs) contain navigational features in a vector format produced by digitizing each feature’s geometry into a specific object. NOAA cartographers collect the vector features using a data standard (S-57) recognized by international treaties and the International Hydrographic Organization. The navigational objects are maintained in a database along with additional information about their real-world characteristics, such as geographic position, shape, color, and age of the data.