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Monday, August 23, 2010

tides



One of the beautiful aspects of doing a long distance tour, is that you get into cycles. Instead of your day be driven by the times that things normally occur - lunch at 12, work ends at 5, dinner at 6. You are more controlled by the natural environment. You tend to rise with the sun, and sleep shortly after sunset. We move in day light, but part of the planning of that move, as well as other things, is dictated by the tide. So first lets discuss the what causes the tides.

Tides are the vertical movement of water - currents are the horizontal movement of water - and that movement of the water is controlled primarily by two forces. The Sun, and the Moon.

You will need to visualize the water covering the Earths surface as somewhat elastic, as it gets pulled and pushed by the sun and moon. First lets start with the moon. The moon has a weak force pulling on the earth, but the moon is relatively close to the earth. When it is over a specific spot, it pulls the water nearest it, and pushes the water furthest away from it.


The sun has a very powerful force exerted on the earth. But it is considerably farther away. But it also pulls the water on the near side of the earths surface to it, and pushes the water on the far side of the earth away from it.

So you have to forces of similar effect - the moon is weak but close, the sun is strong but far away - pulling and pushing the water on the surface of the earth.

But now we have to add movement. The Earth spins on it's axis once every twenty four hours. The moon revolves around the earth once every 28 days. At times the moon and sun are aligned on the same side of the earth. At times the Moon and sun are on different sides of the earth, and at times the sun and moon are at ninety degree angles to each other. This movement combined with the earths rotation is what causes our tides.

In one twenty four hour cycle - in most locations - we have 4 tides. Two high, and two low. These are further broken down to a high high, and low high. (two high tides of different heights) and a low low, and high low (two low tides of different heights)



This is how tides work in the most simple of forms. This is enough for our purposes in that it will give us the back ground to understand how the tides move, and effect us in our kayaks. The tides flow continuously. With no beginning or ending. Only changing in their height, and even those have a never ending flow to them. There is no effective way to fight the tide as a kayaker, we have to get into rhythm with the tides, and use them to our advantage. We can use them in planning our movements, when to leave a beach, when to arrive at another. When it is a good time to move past a shallows, or an area of strong tidal current. Yes, tides can have currents associated with them, but that is for another post. get into the zen of your tide, as it will make for a happier life working with it, in harmony. Than working against it.

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