Tide tables are just a prediction of the action of the tide. Take it too literally and you may end up in trouble. This is one unfortunate on the Medulse Rocks.
High tide time predictions are given in the Sailing Calendar, the club yearbook, and the table at the bottom of every web page, for high tides occurring while the boatman is on duty. These predictions are based on information from Belfield software. The times will differ slightly between all prediction systems. Links to various different prediction systems are given below, so you can check them for yourself.
Many things can affect the predictions but the key ones for us at Granton are:
– The flow of the river – increase flow from upstream can push up the tide or impact the timings
– Atmospheric pressure – The effect of air pressure on tidal height is substantial and all too easy to forget. Tide tables assume a standard pressure of 1013 millibars. Roughly a change in pressure of one millibar will change the sea level by one centimetre.
Forth Ports Authority information:
See “wind and tides” widget in the sidebar. One of the links is to a pdf file which will download (and/or open in a new window) listing tides for the year at Grangemouth, Rosyth, Leith, Burntisland, Methil, Dundee, River Tay bar. TIMES IN GMT.
Here are a couple of the more useful tide predictions for us. (They will open in a new window). Don’t forget that these may need adjusting for BST (unlike the tables in the handbook).
Shows times for Granton corrected for BST when necessary: Granton Tide Times
Tides from Easytide
High and Low water times for Leith (28 Days) from the National Oceanography Centre
Tide Plotter software is now available for Windows and Android. Its developers have been testing the Android version for some time at sea in a sailing environment. It does not require internet access after the initial installation and carries data through to 2020, depending on what you pay, for the UK and Ireland.
Full details and installation from Keith Belfield, Belfield Software: click here
Some electronic chart packages have tidal information, including Navionics both on tablet and in chart plotters.