Years of knowledge have been passed on to me, this scientific and long process of tide estimation is no secret anymore. I’ve always wondered how you could predict without internet access and local book when was a good time to enter that pass or along will it take to get out of that sandbar you just got stuck on.
Those experienced sailors have a way to be able to predict two days ahead from the middle of the ocean, when they will make land fall. So I took the time to pick the brain of one of them. Let me share with you the experience : You will need to review your fifth year’s university math class, and then you will need to get your hands on some document for all the reference station of the world. From there you can extrapolate your particular location of interest. This requires 3 hours of calculations, and a certain degree in masochism. For a result, that by now you are really not sure about.
The other way around all this, is by just getting a little program called wxtide32 . Sorry! I couldn’t resist, if you thought I was going to be able to tell you how to do a prediction of tides and currents, I should inform you that my math skill is limited to the accounting one, enough to make a living but not to make fancy graph and all.
In other words, the secret is out! In the end, you don’t really need to do anything just install properly this little application. Set it up the way you want to show, play with it and you are an expert in no time. I know even the “apple product” have an application for it, however, let’s try this magic device in the middle of the ocean with no cell reception! My duty is done I have passed my knowledge, good luck to you!
Now why, do we travel to Grand Manan for our 49th Island at the entrance of the place on heart with the highest tide, the Bay of Fundy.
The average tidal range of all oceans around the globe is 1 meter (3ft), so how can the tidal difference in the Bay of Fundy reach up to 16 meters (52 feet)? This tidal phenomenon exists because the bay has a few distinct features: a substantial amount of water and a unique shape that causes resonance.
A liquid in a basin has a characteristic period of “oscillation” and, once set in motion, the liquid will rhythmically slosh back and forth in this time period. The surface rises first at one end, then at the other, while the level in the middle remains nearly constant. The speed at which it oscillates depends on the length and depth of the basin. On a small scale, picture water sloshing around in a bathtub. It takes just seconds to slosh back and forth. Due to the unique funnel shape and immense depth of the Bay of Fundy, its natural period of oscillation is somewhere between 12 and 13 hours.
That oscillation is in perfect sync with the Atlantic ocean tide flooding into the bay every 12 hours and 25 minutes, this results in “resonance”. Imagine someone on a swing, going back and forth, reaching the same height every time. Now imagine someone else giving the person on the swing a solid push every time the person starts to move forward again. They are obviously going to go much higher this time. Well, the water in the Bay of Fundy is like the person on the swing and the tides coming in from the Atlantic Ocean are like the person giving the push. It’s because the water in the bay moves back and forth in sync with the oceanic tides outside that there is such a large increase in the tidal range towards the head of the Bay.
The bay’s shape and bottom topography also have a secondary influence on the tides. The bay is shaped like a large natural funnel; it becomes narrower and shallower towards the upper part of the bay, forcing the water higher up onto the shores.