Tidal currents play a very important role in aiding progress in a kayaking journey, or on the flip side it can make life rather difficult when wrongly interpreted. This series of blogs will progressively look at what causes tides and the different variants that can affect the planning of kayaking trips in Langstone harbour.
Firstly tides are primarily caused by the gravitational pull of the Moon and the rotation of the Earth (this is often forgotten). The Sun also plays an important role in working with or against the Moon, which will be discussed later in this series of blogs.
In figure 1, the light blue area illustrates the position of high and low water on Earth and the position of the Moon. You can see there are two high and two low water positions at any given time. If our position on Earth is identified with the star you can see we currently have high tide which is shared with the other side of the Earth.
If we then consider the rotation of the Earth, within 6 hours the Earth and star will move one quarter of a turn which will then give us a low tide. This can be seen in figure 2. This therefore gives us a rough rule of thumb that the time between high and low water is six hours, as within another six hours we would rotate another one quarter turn and have another high tide.
As we already know the moon travels around the earth which takes 28 days and delays the high and low water tide times by about 50min every day. As you can see in figure 3, the Moon has moved but also notice how the bulge of water has moved with it. Therefore the star on the Earth will take an extra 50min before it reaches high tide.
In the next blog we will look at how the Sun also plays a big part in planning a kayak tour in Langstone Harbour.
The Adventure Brand provides a variety of kayaking tours and courses, whether you’re seeking personal guiding technical and safety skills or coaching. Importantly Chichester Harbour, Langstone Harbour, Portsmouth Harbour and the river Hamble provides an excellent teaching and learning environment for kayaking of all abilities. For more information click here or contact Ellis Bird at email@example.com.