The Tides of Anglesey

The Island of Anglesey is a rather special place. I’m sure those of you of you who know it well will agree with me, that it has a very special feeling about it that you can’t quite put your finger on. It maybe the beaches and white sands with the sea lapping on the foreshore, or it might be the mountains and wonderful undulating landscape that does it for you. But what ever it is, it holds a special place in your heart I’m sure. For those of you reading this from afar, and you haven’t visited Anglesey yet, it’s something about island life that has an old, unspoilt, simple way about it that’s stepping back in time to the real import stuff in life, like nature, family and wild life.

I’ve been blessed to grow up on an Island, and be part of island life, and it really shapes you in a different way than most others. You learn to fish, hunt, forage, climb, surf and be at one in nature in a very beautiful way. In a modern day civilisation thats lost in digital devices and distraction, it is an anchor for me to return to and connect to the real things.

One of the real things about island life is one of the things most people don’t even recognise as significant if they are visiting here and are unaccustomed to the ways of island life. That real thing is the tides. The tides of Anglesey are a very integral and powerful force that shapes the way we live, the way we play and connect to the ocean in so many ways, but it goes unnoticed to most if you don’t have the deep connection to the ocean that some of us have.

At 22 years old I went to Bangor university to study oceanography as a mature student, and it was one of the best decision I have ever made in terms of learning about the beautiful powerful force that ha shaped the past and the present landscape, culture and environment we live in. We learnt all about the chemical compositions, the geological component and the biological components of the ocean environment as well as the physics and maths which controlled it. Learning about earth and ocean sciences is both a pleasure and so important for islanders. Our environment is unique in so many ways, and understanding this has many benefits for us to pass on to future generations for sure.

The Tides of Anglesey are a huge huge part of life here and have been for the past 10,000 years. The area that we live in has the second largest tides in the WORLD, yes thats factually correct. We live in an area that has enormous rise and fall of the tides twice a day, each day, all year long. The size of the tide refers to the heigh difference between the low water mark and the high water mark on the foreshore. Our forefathers built settlements here on the foreshore so they could forage just a stones throw away from the low tide marks and feed their families day in day out. Some of the settlements I have found (over 5,000-7,000 years old) sit literally on beach, where camps would have been set up.

To understand how we measure tides, ill give an example. If you where to stand at low water looking up at the beach and project a few meters above your head, this would be how the industry measures the high and low tides as you see it in the charts. It’s the volume of water (measured in meters), above a fixed point at the low water mark on the foreshore. Most of the tide measurements are taken from Liverpool bay and Holyhead which has equally large tides if not greater than Holyhead (the other geographical significant point off Anglesey) that tides are referred from.

Tides can be imagined as a slow wave flooding in over an area of coastline over a period of time. My university professors described it in this way, and it made a lot of sense to me. Just as a wave hits the foreshore and rolls in quick, the tides are like this but a super slow progressive movement of water, that that rolls in and out (but without the crashing wave part!)

The tides of Anglesey have two high waters and two low water each day over a diurnal daily tidal cycle and are spaced out at 6 hour intervals over 24 hours. So if High water was at 12pm, Low water would be 6pm, The next high water is then 12am and Low water is a 6am and so on, so forth. The tides, creep an hour forward each day, which means in the above example, in the first high water (12pm) on the next day would be an hour later at (1pm).

The tides on Anglesey actually only move for 5 hours and 30 minutes each way each tide, and then they turn and create a period of slack water where there is very little residual flow in current terms. The slack water is the time lag between the turning directions between tides.  The incoming tide is referred to as the Flood tide and the retreating tide is referred to as the ebb tide in nautical terms.

Current flow and tides of Anglesey. The speed that the tide moves in and out varies massively from location to location and at various points during the six hour cycle. The faster periods of tide occur usually 2 hours to 4 hours into the flood tide, and then it slows down as it approaches high water. This rule again varies from geographical place to place, but if I’m fishing or sailing on Anglesey, this is my rule of thumb.  The speed of tides is kind of crucial say if we are fishing as when the tide is running to hard, our weights won’t hold bottom at all. Equally the we are sailing we don’t want to have to punch through the tide and have to much resistance where we. High waters on charts are either referred to from Holyhead or Liverpool, the reason is that both of these ports are significant and used for deep water draft vessels.

The size of tides on Anglesey. The tides here on Anglesey increase in size and build up for 1 week, reach their maximum size and then decrease again in size for 1 week. So we get two large tides called Springs and two small tides called neaps a month. They run : Spring, neap, spring neap. The spring tides here on Anglesey can be up to 34ft or 10- 11m in rise and fall, neaps are usually 24ft or 7-8m. Spring tides occur on the new and full moon cycles, and neaps occur at the half moon stages in its visibility from planet earth.

The moon and sun and how they operate the tides. The two objects that control our tides the most (according to present day physics) are the moon and sun. Both exert a gravitation force that acts as a drag the oceans around the globe as they go. The best way to explain this is there is a lunar tide and a solar tide. When the moon and sun are in conjunction (new moon or full moon is in line with the sun) then the two celestial bodies exert the most force on the tides and create the greatest sized tides. Equally when the moon is a half a crescent and is at a right angle to the sun then we get smaller tides called neaps. So spring tides occur on full and new moons, neap tides occur on half moon presents.

Power from tides.  I have worked along almost every square inch of the coastline of the Uk and most of Norther European and the tidal power is amazing in so many ways. It varies in power significantly from point to point, but it always flow, every day 24/7 365 days a year. Back ten years ago I was learning about the amazing possibilities of tidal power, which was being stalled by the idiots protecting their vested interests in oil. The Tech was new but very interesting and cutting edge back then. Ten years on we have made HUGE leaps and are ready to harness the power of tides across the world, which is a game changer. NO more need for dirty oil.. On the Island of Anglesey we are partaking in one of the biggest global, experiments and underwater tide farms by Minesto.This is a game changer for power and our island is at the epicentre of it.

Foraging and the foreshore. The low waters on spring tides provide us with an excellent opportunity to gather foods, and to forage the foreshore. My months are usually blocked out over spring tides and you’ll find it hard to find and contact me (as most of my friends will attest to!) As I’m out gathering bait, foraging and collecting food. The is nothing more in the whole world that I like more than exploring low waters marks on big extreme tides. You get a sneak peak of what lies beneath the illusive ocean, It fascinates me more than anything else on this planet.

See if you can time your visit or if you a local, get to know when are the high and low tides in our area and seek them out to explore. You can find so much out about a location and its environment by exploring the foreshores at low water. I like to go for seaweeds, old fishing tackle (I get hundreds of weights, lures, tackle and bags of line of the beaches) as well as big crab, lobster and bait as in razor fish, crab and worm of all varieties.

I go to look at the sand bars and the sea bed bathymetry to see how the winter storms shape it and change it over the winter months. One either things that id like to start doing is metal detecting there too, for the treasure that lies beneath.

How we use the tides on the island.  We fish, we forage, we explore, we sail and we walk along the low water marks.. How I use the tides is simple, to play, eat and have fun. High waters you can head out for a surf, use the tide to help push your sailing vessel in the direction you want. I spear fish as the tide is rising about two hours up from low water or a little more. I fish from beaches from low water to nigh waters on most locations and the opposite on the rock marks.

Fishing and effects of tide on fish. So how do tides effect finding and catching fish? Well in short, they effect fish and fishing in a big way. Fish move into shallow tidal regions over high water and explore their feeding grounds. They retreat into deeper water during LW and sit the tide out. Getting stranded isn’t an option as a fish, its bad for your health! As the tides rise and estuary’s and bays fill up with water, the fish move in to eat. On deeper water regions offshore the fish stay put, but will only feed on certain states of the tide. They use the tide to move from location to location as a mini bus if you like as well, not exerting any more energy than they need to, to move about.

Areas of fast tidal races in Anglesey. Areas that have the biggest and fastest tides – Swellies, The Skerries, South Stack (Ynys Lawd), The Fangs and Carmel head. These areas a from favourites with some of the kayaking community, such as Nigel Dennis kayaks groupwho go actively play on the tidal races at peak flow. It’s brilliant to watch.

Equinox Spring tides. So twice a year, there are really large tides here in the UK and specifically north Wales. The spring and autumn equinox. They both create huge tides, which means, the rise and fall is greater than any other time of year, so, the tide goes much further out. Now when you combine this with a high pressure system (warm, still weather), you will see the tide go out even further again.  The spring equinox tides have just been and gone here (March 23-25th) and they where huge this year. I went out and salvaged much discarded and lost fishing tackle from the foreshore as I could. I think I bagged over 50 lead weights. I have only seen the foreshore this low once in my life before. When all the factors combine to give, the correct weather over the equinox, you get to see very large astronomical tides.

Things to be mindful of… Ok so now you all know a fair bit about the tides of Anglesey, one thing to take real care of when you explore low water especially on spring tides is, don’t get stranded when the tide comes in. I know these parts like the back of my hand and even I can get caught out late in the eve. So rule number 1, don’t venture exploring too late towards darkness, you can get into bother. 2. Go with some or at least tell someone where you are going.. 3. Pick up some plastics as you (take a bag with you) 4. Take a mobile with you. 5. Always know when the low tide is and when it will turn. 6. Remember that spring tides move in very very fast, so if your out past the tide line, water  can creep around you without even knowing about it.

Some simple ways to keep yourself safe on the foreshore.


Couple of resources for you all :

Where I check my tides all the time :Tides for fishing 

Best weather forecasts – XCWEATHER . Don’t just use the BBC, its such a poor forecasting site- they don’t understand the tiny variations you get on island weather patterns.

So make a note in your diary of the next spring tides and head to the foreshore over the low water  and enjoy our islands its tides.

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Tan Y Tro Nesaf  / Until the next time,


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