NOAA Tide Tables

NOAA Tide Tables: Learn how this product has evolved over the past 150 years.

Tidal predictions are an important part of life for coastal communities in the United States. Commercial and recreational boaters who live, work and play on the coast use tidal forecasts to navigate safely through high and low ocean tides every day. Many coastal journals, fishing guides and tourist publications contain tide and current forecasts derived from NOAA data.

Tide tables in the United States have evolved and grown over the past century and a half. The US Coast Survey first published tide tables for East Coast locations in 1853 in its appendix to the Annual Report of the Superintendent of the US Coast Survey, which noted that it was “not only of laborious observations to collect, but even more work to calculate … the results are not yet in a condition to present scientific data, but the rapid progress made in putting them in this form justifies the belief that they may soon be thus prepared, and meanwhile the tables presented … have a practical value which induces their publication.”

It was not until December 1866 that Coast Survey began printing the tables as an independent publication. The first edition, for the year 1867, separated the forecasts for the Atlantic coast and the Pacific coast of the United States into two publications and gave only the daily high tides. Low tides were added in subsequent years, as were tidal current forecasts. By 1896, the tables included tidal data for ports around the world through data exchanges with other countries.

Printing tide tables continued for 100 years, but with the advent of the Internet in the mid-1990s, the Center for Operational Oceanographic Products and Services (CO-OPS) turned to providing Tide forecasts exclusively online and on CD. CO-OPS continued to generate annual tide tables and tidal current forecasts, but private publishers began printing and distributing hard copies annually, as they still do today. Many third-party Internet applications also use this data.

Over the years: Changes in the calculation of the tide tables

For the first generations of tide forecasts and tide tables, oceanographers calculated all the tide forecasts using auxiliary tables and curves constructed from the results of tide observations at the various ports. In 1882, computing became simpler with the advent of a mechanical tidal forecasting machine by American meteorologist William Ferrel and mathematician Rollin Harris of the US Coast and Geodetic Survey.

From 1885 to 1965, Coast Survey and its successor agency, Coast and Geodetic Survey, used the Ferrel machine and a No. 2 second generation tidal prediction machine to calculate tidal data. The second machine, dubbed “Old Brass Brains” – still rests at NOAA headquarters today. Numerical calculations of tidal predictions began in 1966, once computers arrived.

What began as a “laborious” but necessary task for NOAA’s predecessors more than 150 years ago has led to a rich history of scientific discovery and ingenuity. Today, the tide tables are published in four volumes: East Coast of North and South America (including Greenland); Central and Western Pacific Ocean and Indian Ocean; West Coast of North and South America (including the Hawaiian Islands); and Europe and west coast of Africa (including the Mediterranean Sea). Instructions for obtaining printed copies of the 2016 tide tables are available online.

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