Understanding Time and Tides

Since time immemorial, we have been fascinated by the regular rise and fall of the sea, and the influence that the moon and, to a lesser extent, the sun have on the water – but it’s not all about poetic inspiration or a spirit of scientific discovery. The bottom line is that for the sea angler, understanding a little of the rhythm of the tides can help you catch more fish, which is about as simple – and as important – as it gets!

Local Tides

Although the tides are driven by the moon and sun, it’s not simply a case of a lot of moving water being dragged about by their gravitational pull. The overall movement is also heavily modified by the land masses around which the water flows and that gives rise to local tides, which vary considerably in the extent of sea they affect. In the North Atlantic, for example, as the water rises around Britain, it falls away from the shores of eastern Canada, while a much smaller tide runs from the North Sea between the coastlines of East Anglia and the Netherlands and a smaller one still exists between Northern Ireland and the Mull of Kintyre in Scotland.

Add to this the effect that adjacent tides can have on each other – cancelling each other out if “high” meets next door’s “low”, or doubling things if they coincide – and the existence of tide-free areas, known as amphidromic points, and it becomes clear why tide prediction is a bit of a specialist job. It also makes it pretty obvious why tide tables are a real must, too!

Tide Times

In British waters, the sea rises and falls twice a day, giving us two each of high and low tides and because of the interaction of the water’s inertia, the earth’s rotation and the orbit of the moon, these tides slightly lag behind the precise 12 hour-cycle you might expect from a 24 hour day. Thus the natural period of our two-tidal system is 12 hours and 25 minutes, explaining why corresponding high and low tides get about an hour later every day.

Spring and Neap Tides

The smaller effect of the sun, however, does tie in with half the length of the Earth’s day – and roughly every fortnight throughout the year, at new moon and full moon, when the sun, moon and Earth are in line, the lunar and solar effects combine, resulting in “spring tides.” The name is a little confusing, particularly since some of the highest “spring” tides actually do occur at the Spring Equinox, but in reality, they have nothing to do with the season; the Autumnal Equinox in September produces equally strong spring tides!

Conversely, when the sun and moon are at right angles to the Earth – in the first and third quarters of the lunar cycle – their respective pulls work against each other, leading to lower than average high tides and higher than average low tides. These are the neap tides.

Tides and Fishing

That’s all well and good, but what does it mean for fishing? The answer to that becomes clear when you stop to think about what’s happening on the shore during those spring tides.

For one thing, most of the really sea-bed-scouring storms tend to accompany spring tides, and while this may not make for the best time to be out there trying to catch fish, it does mean that a lot of possible food items become exposed as the bed is churned up. Once the weather has calmed down, this can often leave fish with unexpected feeding grounds and if you know the likely spots, you can add your own bait to the bonanza harvest they’re enjoying.

Even when there aren’t any major storms, high water during a spring tide frequently tempts fish closer in to shore than usual and the deeper water can sometimes bring unexpected – and occasionally surprisingly large – guests within reach of our lines.

Looking at the other side of the coin, the low water of a spring tide exposes more of the foreshore than normal, so it’s an ideal time to do some reconnoitring of the sea-bed with an eye to finding promising spots to try in future. A good knowledge of local conditions can sometimes make all the difference between success and failure, so take the opportunity to get to know your patch at these times; it can pay big dividends later.

They say that time and tide wait for no one – and of course, it’s true – but that doesn’t mean you can’t get a bit of a helping hand if you understand a little of what makes these natural cycles tick!