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NOAA's Office of Coast Survey

NOAA navigational tools and charts

World Hydrography Day is June 21

A Day to Recognize Ocean Surveyors

June 15, 2011
image of hydrographic surveying map of seafloor

Mary Glackin, NOAA's Deputy Under Secretary, honors the nation's hydrographers as she explains how hydrography supports the U.S. economy, keeps mariners safe, and protects our coastal communities and ecosystems. (video)

Map showing the distribution of the slave population of the Southern States of the United States. This map was compiled from the 1860 Census.

Hydrographers have historically played an important role in America. During the Civil War, following the Confederate evacuation of Charleston in 1865, hydrographers identified obstructions to the harbor, facilitating the resumption of commerce. Use your mouse to explore the map.

Coast Survey vessel

NOAA hydrographic vessels survey the nation's coastal seafloors, determining water depths and searching for dangers to navigation.

World Hydrography Day, celebrated in maritime countries around the world, is a time to recognize the ocean surveyors who map the oceans. Thanks to hydrographers — in NOAA, in other federal agencies, and in private industry — this nation's safe and efficient maritime transportation system supports increased trade and economic growth for American industry and agriculture.

NOAA hydrographers measure oceans depths and search for underwater dangers to navigation, acquiring data for the nation's nautical charts and ocean models. They have a long history of service to this country, beginning with President Thomas Jefferson's Survey of the Coast in 1807.

Hydrographic products continue to support updated navigational tools and charts, but today's data is used far beyond purposes envisioned in prior centuries. From helping scientists understand the movements of tsunamis, to characterizing essential underwater habitat for healthy fisheries, today's hydrographers contribute, more than ever, to a healthy ocean, vibrant coastal communities, and a growing maritime economy.