About RNC Charts
An RNC chart is a chart format that can be displayed using marine navigaion software. NOAA and MapTech provide offshore and inland waterway RNC’s for all of the United States.
Raster Charts
In the United States, all official nautical paper charts produced by NOAA’s Office of Coast Survey (OCS) are available in raster format. A fundamental tool of marine navigation, NOAA’s Raster Navigational Charts (NOAA RNCsâ„¢) are produced by scanning at high resolution the original color separates, which are used to print the paper charts. NOAA adds to the digital raster file such features as data describing the chart, its datum, projection, and its geo-reference. Geo-referencing enables a computer-based navigation system that is connected to a GPS to locate and display on the chart image on screen the vessel’s exact position.
Computer-based navigation systems that use official raster data, such as NOAA RNCs, may also be referred to as Raster Chart Display Systems (RCDS). RCDS use raster nautical charts and electronic positioning to provide an integrated navigational tool. Today, national hydrographic offices such as OCS endorse the use of RCDS to enhance safe navigation. RCDS’s offer the mariner functionalities, such as real-time positioning — the ability to use the familiar chart image and show at an instant exactly where one’s ship is in relation to its charted surroundings. Existing raster navigation software interfaces with electronic positioning systems including GPS and DGPS. These powerful navigation tools support voyage planning and monitoring (routes, way points, off-track alarms, log books, voyage recording,…), access to chart notes, access to large suites of charts on-line, bearing and distance calculations, subdued night colors, and much more.
RNC Publishers
The NOAA RNCsâ„¢ distributed here are geo-referenced, full-color images of NOAA’s paper nautical charts, published by NOAA in the .BSB format. NOAA updates the RNCs for Notices to Mariners on a weekly basis. They are an official product of NOAA, and meet the S-61 Standard, “Raster Navigational Chartsâ€, of the International Hydrographic Organization.
In the future, NOAA plans to distribute the same images in a geoTIF format from this website. These images will not be considered as NOAA RNCsâ„¢, are not updated for Notices to Mariners, and do not conform to the S-61 Standard.

