Hydrographic surveys are performed by NOAA ships using multi-beam and side-scan sonar systems to determine water depths, submerged dangers to navigation and obstructions. (Photo credit: Lt. Jon Swallow)

The use of marine navigation tools is necessary to ensure safe and efficient marine transportation and commerce, offshore engineering projects, naval operations and recreational activities. The Office of Coast Survey, which is part of NOAA's National Ocean Service (NOS), is responsible for providing these tools, such as nautical charts and hydrographic surveys. These must be kept accurate and up to date at all times.

Authorizing Mandate

The mandate to create nautical charts of the nation's coasts dates back to 1807, when President Thomas Jefferson ordered a survey of the young nation's coast. The Organic Act of 1807 authorized the newly formed coastal survey agency to construct and maintain the nation's nautical charts. This agency, the Office of Coast Survey (OCS), is the oldest scientific organization in the U.S. It has been a part of NOS since 1970, when the National Oceanic and Atmospheric Administration was created.

The mandate to create and maintain nautical charts and related hydrographic information is meant to ensure safe navigation of maritime commerce within the U.S. Exclusive Economic Zone--an area of 3.4 million square nautical miles offshore from the coastline.

Coast Survey's Activities

This Coast Survey cartographer (or map-maker) is preparing an electronic navigation chart, which will be used by mariners to lay out courses and navigate ships by the shortest and most economically safe route.

Nautical Charts

Today, OCS remains the primary agency responsible for constructing and maintaining the nation's nautical charts. Nautical charts contain information about the nature and form of the coast, the depths of the water and general character and configuration of the sea bottom, locations of dangers to navigation, the rise and fall of the tides, locations of navigation aids, and characteristics of the earth's magnetism. Nautical charts are available in paper format, in a raster format (georeferenced digital pictures of paper nautical charts), and electronically.

Hydrographic Data and Coast Pilots

In addition to providing nautical charts, NOS collects marine hydrographic data to construct and maintain more than 1,000 nautical charts and Coast Pilots, which are a series of books that cover a variety of information important to navigators. Hydrographic surveys contain water depth data that emphasize elements affecting safe navigation. These surveys identify sea floor materials, dredging areas, cables, pipelines, wrecks, piles and fish habitats using multibeam and side-scan sonar tools. Coast Pilots include channel descriptions, anchorages, bridge and cable clearances, currents, tide and water levels, prominent features, pilotage, towage, traffic separation schemes, small-craft facilities, and federal regulations that are applicable to navigation. Coast Pilots are also available for download. Ongoing research and development efforts aim to improve NOS's marine navigation products and services.

NOS explores and develops new and efficient techniques to improve charting and hydrographic operations and to promote safe navigation. This digital graphic combines NOAA's bathymetric data with the U.S. Geological Survey's topographic data to three-dimensionally display the land/water interface. Scientists use graphics like these to model possible storm surges, study how sediment is transported and deposited, assess habitats, and delineate shorelines.

NOS's Navigation Response Teams conduct hazardous obstructions surveys. Working from 10 strategically placed offices, the teams are available on short notice, and use dive operations, electronic navigation data collection and mapping support capabilities to promote safe navigation in emergency situations 365 days a year throughout U.S. waters.

NowCOAST--An Internet Mapping Portal

NOAA's NowCOAST is an Internet mapping portal that provides spatially-referenced links to real-time information from meteorological, oceanographic, and river-observing networks, as well as NOAA's weather and marine forecasts and forecast guidance for major estuaries and seaports, the Great Lakes, and coastal regions. Within a mouse click, users can access thousands of real-time observing stations and forecast locations.

These nautical charts for Chicago from 1911, 1922 and 1926 are in NOAA's online collection of more than 20,000 maps and charts from the late 1700's to the present. Historical maps, such as these, are sometimes used to understand how shorelines, or other features, have changed over time.

Historical Maps and Charts Collection

NOS makes available more than 20,000 maps and charts dating back to the late 1700's. The collection includes the nation's earliest nautical charts, hydrographic surveys, topographic surveys, geodetic surveys, city plans and Civil War battle maps. Maps and charts are scanned and made available via the Internet.