![]() You can tell when a spring tide or neap tide is happening without being anywhere near the water. About a week later, when the Sun and Moon are at right angles to each other, the Sun’s gravitational pull works against the Moon’s gravitational tug and partially cancels it out, creating the moderate tides called neap tides. Twice a month, when the Earth, Sun, and Moon line up, their gravitational power combines to make exceptionally high tides where the bulges occur, called spring tides, as well as very low tides where the water has been displaced. But it’s a distant gorilla, about 390 times farther away than the Moon, which gives it a little less than half of the Moon’s tide-generating force. The Sun ― with about 27 million times the mass of the Moon ― is always the gorilla in the room when it comes to solar system equations. Now, the Moon is the biggest influence on Earth’s tides because of its proximity ― but it isn’t the only influence. To get a true estimate of the tides near you, you’ll have to check the local tides forecast. The tides we actually see at our shores are affected by everything from the shape of Earth’s continents to wind and storms. In addition, Earth isn’t a perfect, smooth sphere. This means that the high tide bulges are never directly lined up with the Moon, but a little ahead of it. When the Moon’s gravity pulls at Earth, the water doesn’t float outward, it just gets pushed and squeezed around on the globe, directed by both gravitational pull and other forces, until it ultimately ends up bulging out on the side closest to the Moon and the side farthest away.Ĭan you easily predict the tides by following the path of the Moon? Not really! First of all, because the Moon is orbiting in the same direction as the Earth rotates, it takes extra time for any point on our planet to rotate and end up exactly below the Moon. It’s easier to slide the water around on the table rather than lift it directly upwards. Now think about pouring a bucket of water out on a table. The strongest pull occurs on the points closest to the Moon, and the weakest on the points farthest away, but every bit of water is affected. This happens because the Moon’s gravity affects the entire Earth, pulling at every point on our planet. It might seem strange that the ocean would bulge on the side farthest from the Moon as well as the side closest to it. The low points are where low tides occur. Just remember spring tides are high high tides and low low tides giving a large tidal range between the two, neap tides are low high tides and high low tides giving a small range between the two.In this simplified animation, Earth’s oceans bulge out on both the side closest to the Moon and the side farthest from the Moon. When the moon and sun are 90 degrees to each other, the gravitational pull is its weakest, thus low high waters and high low waters, this is neap tide. Simply put, when the sun and moon are in line with the earth, the gravitational pull is at its greatest. This means that high waters are very high and low waters are very low. ![]() ![]() Both the moon and the sun pull at the earth’s bulge of water and this is what causes tides. The tides are governed by earth's position in relation to the moon and sun. We know the tide rises and falls, giving us high tides and low tides but why does this happen? ![]() Tides are very stable and can be predicted with a fair amount of certainty, hence tide tables that can be found in the Almanac, tide table booklets, or on tidal Apps. It could also be imperative to get into a harbour at high tide rather than at low tide where it may be impossible. Tides are an extremely important factor in the sailing world. It is important to have a basic understanding of how tides work because it can be the difference between a fantastic, smooth fast passage, or a boring, slow and potentially lumpy one. ![]()
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