A 'tide table' is used for
tidal prediction and shows the daily times and height of
high water and
low water for a particular location. Tide heights at intermediate times (between high and low water) can be approximately calculated using the
rule of twelfths or more accurately by using a published tidal curve for the port.
Tide tables are published as small booklets in their own right, as part of
nautical almanacs, on the
Internet, in some
newspapers (generally those serving readers in coastal regions or having maritime interests) and as the output of tidal prediction
software.
Often tide tables are only calculated and published for major commercial
ports called
standard ports. The tides for other minor ports can be calculated simply using a system of time and height "differences" between the Standard port and the nearby minor ports.
The dates of
spring tides and
neap tides, which have an interval of seven days, can be determined by the range of the height of the tide on the tide table; a small range indicates neaps and large indicates springs.
On the
Atlantic coast of northwest
Europe, the interval between low and high water is usually a little over 6 hours, giving one or two high waters each day and one or two low waters each day.
External links
★ http://www.waterlevels.gc.ca/english/Canada.shtml Canadian tide tables
★ http://www.getij.nl/ Dutch tide tables
★ http://www.bsh.de/de/Meeresdaten/Vorhersagen/Gezeiten/index.jsp German Bight tide tables
★ http://www.bbc.co.uk/weather/coast/tides/ UK tide tables
★
Australian Tide Times
★ http://tidesandcurrents.noaa.gov/ US tide tables (NOAA)
★ http://freetidetables.com/ US tide tables