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Tides online (

Theory of Tides ( The word "tides" is a generic term used to define the alternating rise and fall in sea level with respect to the land, produced by the gravitational attraction of the moon and the sun. To a much smaller extent, tides also occur in large lakes, the atmosphere, and within the solid crust of the earth, acted upon by these same gravitational forces of the moon and sun.

Permanent Service for Mean Sea Level ( Welcome to the Permanent Service for Mean Sea Level (PSMSL), hosted by the Proudman Oceanographic Laboratory (POL). The PSMSL was established in 1933, and is the global data bank for long term sea level change information from tide gauges.

NOAA Center for Operational Oceanographic Products and Services ( The National Ocean Service (NOS) Center for Operational Oceanographic Products and Services (CO-OPS) collects and distributes observations and predictions of water levels and currents to ensure safe, efficient and environmentally sound maritime commerce. The Center provides the set of water level and coastal current products required to support NOS' Strategic Plan mission requirements, and to assist in providing operational oceanographic data/products required by NOAA's other Strategic Plan themes.

Real-time Port Data ( The Physical Oceanographic Real- Time System ( PORTS ® ) is a program of the National Ocean Service that supports safe and cost-efficient navigation by providing ship masters and pilots with accurate real-time information required to avoid groundings and collisions.

Retrieve Observed Water Levels (

Sea Level Trends Along US Coasts ( The rate of mean sea level rise or fall has been determined for 117 long term water level stations. Monthly mean sea level data were used to obtain the linear trend, the average seasonal cycle, and the interannual variations. The linear trend at a coastal location is primarily a combination of the global sea level rise and any local vertical land movement.

University of Hawaii (

    Sea Level Center Data ( The University of Hawaii Sea Level Center (UHSLC) provides three online databases; the research quality data , the GLOSS/CLIVAR "fast delivery" data , and the JCOMM Sea Level Program in the Pacific map data .

    Tsunami Information for Hawaii (

University of Colorado Global Tide Model (

University of Texas Center for Space Research Global Sea Level Data (

Revised on: 4 February, 2005