TIDES IN THE GANNEL Safety around the sea and rivers is essential and if we know how the tides work it will give us a better understanding and respect for one of the awesome feats of mother nature. Tides exist everywhere, though mostly noticeable in the sea. Tidal Range The tidal range is the vertical height between lowest and highest sea levels. Many places in the world this is less than a metre (3′). But the biggest tidal range in the world is over sixteen metres (50’+), The north coast of Cornwall has a range of about 8m (25′) and this diminishes to around 6m (19′) at the tip of Cornwall and stays about the same along the south coast. As you can imagine, 6-8m is a big variation in water level, if you picture it on a harbour wall for instance, or regarding water depth in one spot. On a gently shelving beach, this vertical change can mean the water comes in and out several hundred metres. Also if you look at the rocks at low tide and see where the seaweed mark stops and then becomes bare rock, this gives you an idea of how far the tide actually comes in. Spring and Neap People talk about Spring & Neap tides, and some people think they are annual things, but actually they happen twice a month. If it’s Spring tides today, it will be a Neap tide in a week’s time. Spring tides are big, but Neap tides are relatively small in comparison – the water doesn’t come up as high or recede so low. The ‘swing’ between high and low water is a bit more pronounced each day until the Spring tide actually happens, then the tide becomes less each day until it becomes the Neap tide. This happens because of more astrophysics. Twice a month the moon and sun are working together, and in between they work against each other. Over a year there’s a smaller variation caused mainly by the tilt of the Earth towards the sun. Equinoxial springs (late March and September) are therefore the biggest we get. Neap tides are characterised in Cornwall by having a high tide at about mid-day and midnight. Spring tides, well they’re usually around 1900hrs, and 0700hrs. Twice a day High tide comes twice in each turn of the Earth (24hrs), with low tides in between. They are approximately evenly spaced. But the time from today’s high to tomorrow’s is about 25hrs, so every event, high, low, whatever, is a little later each day. Tide Tables All of the tide times for all areas such as our local area are in a small yellow booklet, available from most shops including garages. From the information inside we can see all tide times for every day of the year. The information will also contain the heights and lows of the tides so usually on the Gannel if the tide is going to be a Spring tide at approximately 0645hrs, you can expect the Spring tide to be approximately 6.8 metres to 7.2 metres you can look at the Gannel and expect the tide to be touching the far bank (south bank) and nearly up the the bottom of the bank on the north (Pentire) side bank. (This may fluctuate slightly depending on the winds). Tide times are available for downloads on most devices such as Apps for phones / ipads etc. Tidal Flow Most people think that the water gets ‘pulled’ up and ‘down’ by the moon and is like the water in a bath when you run the taps or take out the plug. The water has to flow from one place on Earth to the next. So there’s a current and in the case of Cornwall the current will be quite a strong one. The incoming tide flows up from the tip of the county, going east as it rises, and then heads west as it drains away. These tidal currents can be fast, too fast to swim against. There will also be even stronger currents as the water is forced up or down estuaries such as the Gannel and tidal creeks (Penpol). Tideline If you look at a beach, you can usually see a line of seaweed and other debris that was left behind by the last high water. This is very obvious along the Gannel over the last couple of days. The next high tide that follows the main Spring tide will be about 10 centimetres lower than that. For about an hour around low tide and high tide, it doesn’t seem to do anything. This is called ‘slack water’, and ‘ebb’ is when the tide is falling, ‘flood’ is when it’s rising. Without getting too complicated and sounding like a scientist, the above information is all we need to know about the tides and how they work, AND why all ages should understand why and how they happen. Understanding this and explaining this to the younger folk in our life will and can save lives but will also enable us all to plan our walks / activities safely and not jeopardise the lives of the volunteers such as the RNLI in risking their lives to save us because we were ignorant of the tides and how they work! Every holiday season you can guarantee someone will get caught out on the south side of the Gannel as the tide rushes in. If you are walking along the estuaries and beaches in the future – always know the tide times and keep an eye out for ‘escape routes’ that you can use in case the tide does rush in.

TIDES IN THE GANNEL Safety around the sea and rivers is essential and if we know how the tides work it will give us a better understanding and respect for one of the awesome feats of mother nature. Tides exist everywhere, though mostly noticeable in the sea. Tidal Range The tidal range is the vertical height between lowest and highest sea levels. Many places in the world this is less than a metre (3′). But the biggest tidal range in the world is over sixteen metres (50’+), The north coast of Cornwall has a range of about 8m (25′) and this diminishes to around 6m (19′) at the tip of Cornwall and stays about the same along the south coast. As you can imagine, 6-8m is a big variation in water level, if you picture it on a harbour wall for instance, or regarding water depth in one spot. On a gently shelving beach, this vertical change can mean the water comes in and out several hundred metres. Also if you look at the rocks at low tide and see where the seaweed mark stops and then becomes bare rock, this gives you an idea of how far the tide actually comes in. Spring and Neap People talk about Spring & Neap tides, and some people think they are annual things, but actually they happen twice a month. If it’s Spring tides today, it will be a Neap tide in a week’s time. Spring tides are big, but Neap tides are relatively small in comparison – the water doesn’t come up as high or recede so low. The ‘swing’ between high and low water is a bit more pronounced each day until the Spring tide actually happens, then the tide becomes less each day until it becomes the Neap tide. This happens because of more astrophysics. Twice a month the moon and sun are working together, and in between they work against each other. Over a year there’s a smaller variation caused mainly by the tilt of the Earth towards the sun. Equinoxial springs (late March and September) are therefore the biggest we get. Neap tides are characterised in Cornwall by having a high tide at about mid-day and midnight. Spring tides, well they’re usually around 1900hrs, and 0700hrs. Twice a day High tide comes twice in each turn of the Earth (24hrs), with low tides in between. They are approximately evenly spaced. But the time from today’s high to tomorrow’s is about 25hrs, so every event, high, low, whatever, is a little later each day. Tide Tables All of the tide times for all areas such as our local area are in a small yellow booklet, available from most shops including garages. From the information inside we can see all tide times for every day of the year. The information will also contain the heights and lows of the tides so usually on the Gannel if the tide is going to be a Spring tide at approximately 0645hrs, you can expect the Spring tide to be approximately 6.8 metres to 7.2 metres you can look at the Gannel and expect the tide to be touching the far bank (south bank) and nearly up the the bottom of the bank on the north (Pentire) side bank. (This may fluctuate slightly depending on the winds). Tide times are available for downloads on most devices such as Apps for phones / ipads etc. Tidal Flow Most people think that the water gets ‘pulled’ up and ‘down’ by the moon and is like the water in a bath when you run the taps or take out the plug. The water has to flow from one place on Earth to the next. So there’s a current and in the case of Cornwall the current will be quite a strong one. The incoming tide flows up from the tip of the county, going east as it rises, and then heads west as it drains away. These tidal currents can be fast, too fast to swim against. There will also be even stronger currents as the water is forced up or down estuaries such as the Gannel and tidal creeks (Penpol). Tideline If you look at a beach, you can usually see a line of seaweed and other debris that was left behind by the last high water. This is very obvious along the Gannel over the last couple of days. The next high tide that follows the main Spring tide will be about 10 centimetres lower than that. For about an hour around low tide and high tide, it doesn’t seem to do anything. This is called ‘slack water’, and ‘ebb’ is when the tide is falling, ‘flood’ is when it’s rising. Without getting too complicated and sounding like a scientist, the above information is all we need to know about the tides and how they work, AND why all ages should understand why and how they happen. Understanding this and explaining this to the younger folk in our life will and can save lives but will also enable us all to plan our walks / activities safely and not jeopardise the lives of the volunteers such as the RNLI in risking their lives to save us because we were ignorant of the tides and how they work! Every holiday season you can guarantee someone will get caught out on the south side of the Gannel as the tide rushes in. If you are walking along the estuaries and beaches in the future – always know the tide times and keep an eye out for ‘escape routes’ that you can use in case the tide does rush in.