"Changing Sea Levels - effects of tides, weather and climate"

 Tidal Predictions

 Several Authorities make tidal predictions available on the web. While most maritime countries issue Tide Tables, usually through their Hydrographic Authorities, for historical reasons the most comprehensive global coverage is available through the United Kingdom Hydrographic Department.

NOAA has a very user-friendly site for tide levels and currents predictions around the United States. Elsewhere see the sites for Australia, New Zealand, France and Canada.

Although annual Tide Tables are still widely published, NOAA, for example, has ceased printing volumes since 1996. They favour private publishing and electronic/web access. This trend will certainly continue, though many users like the tangible printed version. Preparation of basic tidal predictions is not difficult, and software is available for doing it, from official sources. These tables are often supplemented by more detail from private sources: there are examples from Canada and Australasia. All national Authorities caution against the use of "unofficial" predictions in case there are errors. Also many Authorities, including the UK Hydrographic Department, maintain strict Copyright control over their predictions, and particularly over the harmonic constants and the subsidiary data on which they are based.

Scripps Institution of Oceanography maintains an excellent portal site on tides and tide prediction.

Well worth a visit!

 You can help develop the site as a resource for other readers by sending suggestions for adding to these pages. I will be updating the material at regular intervals, and will gladly acknowledge the sources of all suggestions that are used.