Tides

Background and definitions

The Insight section of the Proudman Oceanographic Laboratory site has a good overview.
The Tides questions Answered section had a very good detailed description of the factors influencing the tides.

"Our Restless Tides" , http://co-ops.nos.noaa.gov/restles1.html , gives a very detailed explanation of the factors behind tides and currents.

In the Ashore section, I link to a Coastal Navigation tutorial site. Section.6 of this opens with a succinct description of the factors infulencing tides - http://http://www.sailingissues.com/navcourse6.html
It then goes on to explain various tidal terms and chart datums with some interactive and graphic elements.

Online predictions

Easytide - from the UK Hydrographics Office

If they don't know, who does? This link is to the main Easytide site. The drill-down to a port is a three-step process, so once you are in, they have a useful option to bookmark your own ports. Ports are UK, Irish and worldwide.

They note that the times to NOT take Daylight Saving Time into account.
Note also that you can only get predictions for 'today' and up to 6 days ahead.

National Tidal & Sea Level Facility

Provided by the Proudman Oceanographic Laboratory, this also offers tides for 'Today' and 6 days ahead
for a range of UK and Irish locations. This is a one-step operation rather than the three-step above. Click on the list or on the map.
It offers some secondary ports not offered by the UKHO site

The Weather section of Yachting and Boating World has a link to 14-day tides at UK and irish standard ports.

XTide: Harmonic tide clock and tide predictor

But first - a rant !
A number of sites used to run interfaces to the program but European ports dropped out of sight during 2001. The problem was that the predictions used tidal data that the UK Hydrographic Office asserted "infringes the intellectual property of the Crown".
This seems a wrong-headed bloody-minded bit of bureaucratic thinking. The limitation would not affect serious and frequent sailors, who would have all the reference books anyway. It would affect casual visitors to the shoreline (bird-watchers, walkers, anglers as well as sailors). Human nature being what it is, this category might not be inclined to invest in something like an almanac just to check tides occasionally. The result will be safety issues.

An interface to XTide with options:

The general index

http://tbone.biol.sc.edu/tide/sitesel.html

Do-it-Yourself

See http://www.flaterco.com/xtide/ports.html , for information and for pointers to versions of XTide for Windows, Palm Pilot, etc.

home