Tide Tables predict the daily times of high and low water together with the corresponding heights of the tides at those times for specific locations around the UK. These locations are known as Standard Ports.
Other locations situated along the coast in between the Standard Ports, are known as Secondary Ports.
Finding the times and heights of tides at Secondary Ports can be calculated by reference to the Standard Port data.
Artwork by Andrew Simpson
In the sketch above ...
MHWS means Mean High Water Springs
MHWN means Mean High Water Neaps
MHLS means Mean Low Water Springs
MHLS means Mean Low Water Neaps
The difference between high and low water on any particular day - the range - is obviously greater on spring tides, when the associated tidal streams are at their strongest. And of course, the opposite is true for neap tides.
This is vital information not just for small-boat anglers needing to know if there's going to be enough water over the slipway to launch and recover their boats, but for all fishermen, whether fishing afloat or from the shore.
Why? Well, just like people, fish have their active times and their rest times. Unlike people, most of whom are active during the day and rest at night, fish plan their life around tides.
As the tide rises and falls, water flows in and out of estuaries and along shorelines, creating strong currents which provoke feeding behaviour in fish. High and low water and the periods either side of them when the tide's neither rising nor falling are known as slack water, and it's during this time that most fish take forty winks. Not normally a great time for fishing, but everyone's usually up and going again about two hours after the ebb and the flood tide begins again.
So an understanding of Tide Tables clearly helps you know where and when to fish - so you need to take a close look at a set for your home port if you're to get the best out of your day's fishing. Tide Tables are produced in several formats:~
Published Tide Tables (paper or electronic), give reasonably accurate predictions of high and low water times for the Standard Ports. But they're not entirely accurate as strong onshore winds can 'hold up' a tide, and strong offshore winds can create a low tide sooner than predicted.
Tides are the up-and-down movements of the oceans caused by the net gravitational effect of the moon and the sun on the earth.
When all three orbs are in line, as seen here on the right, the gravitational effect is at its greatest and tides are highest.These are known as spring tides and occur twice each month.
Conversely, when the moon and sun are at right angles to each other as seen from the earth, the effect is at its weakest and tides are correspondingly smaller.These are known as neap tides, and occur midway between spring tides.
In most parts of the world there are two high tides and two low tides every day, with approximately six hours between them. However, anomalies do exist. Here in the UK for example, a second high water occurs during the tidal cycle between Poole and Southampton. This is apparently caused by the funnel-like shape of the English Channel and the topographical features that exist locally - the effect is clearly apparent from the Tide Tables for this region.
Tidal streams are currents caused by the rise and fall of tide. Generally the currents flow one way during the flood tide and the opposite during the ebb tide.
But a mile or two offshore, the time when the tidal current is about to change from one direction to the other - slack water - whilst related to the time of high/low water at the Standard Port, does not coincide.
And this is where Tidal Stream Atlases come in. These have 13 pages of chartlets - giving a picture of what's happening at the time of high water at the Standard Port, and at each hour either side of high water.
Armed with a Tidal Stream Atlas for your local area and a set of Tide Tables you'll always know what the tide is doing - and when it's doing it.