where the tide ebbs and flows twice in twenty-four hours?
970700
It's not exact, or we wouldn't see phases of the moon. See, the moon is a significant influence on times of ebb and flood tides, and if it was perfectly synchronized with our rotation, then it would be the same phase every day.\n\nFurthermore, it changes every day at each location. For the most part, you can count on a 5 or 6 hour flood stage from low to high tide, followed by a 5 or 6 hour ebb stage back to low tide.\n\nOther forces effect tides (such as the sun's gravity), but as far as time of day for high and low tides, nothing compares to the moon's gravitational tug.
1134387
While the high tide is coming in the waves will be bigger with the "tidal push".  The morning usually has better shape unless you have afternoon offshore winds.  Winds that blow onshore tend to flatten the waves and ruin their shape.
587803
The moon's gravity as felt on earth is indeed much weaker than that of earth, but it acts on the entire area of the earth, in particular on the earth's water layer, a shell 8000 miles in diameter. This weak but widespread gravity force raises slight bulges only a few feet in height, a small distortion of such a huge shell. The two bulges are located close to the areas nearest to and farthest from the moon, the points of greatest and smallest moon gravitational pull. Rotation of the earth causes these bulges to travel around the earth's water layer. Tide can be thought of as an extremely long wave that occurs at predictable times (about twice a day) with predictable amplitudes. Resonant sloshing in the ocean basins amplifies the water height disturbances on shore.\nThe greater tidal amplitude at full and new moons is due to the additive effect of solar gravity when the sun, earth and moon are all more or less in line. Incidentally, the size of ordinary waves is only marginally related to tides.
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I get what you're asking. The answer is that the tidal cycle from high water to low water is a little longer than twelve hours long. Because of the earth's tilted axis (that's what causes summer and winter) the tidal cycle is not a simple sine curve and the two daily high tides are not equal in height. This cycle repeats on a 14 day period. Anyway, since the Atlantic coast is only 4 hrs different that the Pacific Coast, there are 4 short periods during each 24 hour day when the tides on the Atlantic coast will be moving the opposite direction of the tides on the Pacific Coast. \n\nTo see how this works, go look at the graph on this page title "Mixed, semi-diurnal tide" and look at any given 4 hour period. You'll see the result. \nhttp://www.esru.strath.ac.uk/EandE/Web_sites/03-04/marine/res_resourcebkd.htm
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140 mph winds and 11 foot tidal surge
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2;55 a m  east coast!
516897
Since the Earth rotates relative to the Moon in one lunar day (24 hours, 48 minutes), each of the two bulges travels around at that speed, leading to one high tide every 12 hours and 24 minutes. The theoretical amplitude of oceanic tides due to the Moon is about 54 cm at the highest point. This is the amplitude that would be reached if the ocean were uniform with no landmasses and Earth not rotating.\n\nThe Sun similarly causes tides, of which the theoretical amplitude is about 25 cm (46% of that of the Moon) and the cycle time is 12 hours.\n\nAt spring tide the two effects add to each other to a theoretical level of 79 cm, while at neap tide the theoretical level is reduced to 29 cm.\n\nReal amplitudes differ considerably, not only because of global topography as explained above, but also because the natural period of the oceans is in the same order of magnitude as the rotation period: about 30 hours. If there were no land masses and the ocean bottom were flat, it would take about 30 hours for a long wavelength gravity wave to propagate halfway around the Earth (by comparison, the natural period of the Earth's crust is about 57 minutes). This means that, if the Moon suddenly vanished, and there were no land, the level of the oceans would oscillate with a period of 30 hours with a slowly decreasing amplitude while dissipating the stored energy. This 30 hour value is a simple function of terrestrial gravity the average depth of the oceans, and the circumference of the Earth.\n\nThe distances of Earth from the Moon or the Sun vary, because the orbits are not circular, but elliptical. This causes a variation in the tidal force and theoretical amplitude of about ±18% for the Moon and ±5% for the Sun. So if both are in closest position and aligned, the theoretical amplitude would reach 93 cm.
289483
tides are a result of the gravitational pull from the moon
257896
Two and one-half hours.
830261
24 hrs, unless it's a Friday or you are in the south.
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3 hours. \n\nIf it takes 12 hours to go from low tide to high tide and back to low tide, that means it takes 12 hours to go from 1.0m, to 3.0m and back to 1.0m.\n\nSo in half of 12 hours= 6 hours it goes from 1 to 3\nAnd in half of that= 3 hours it goes from 1 to 1.5.\n\nTry drawing a wave starting from the lowest point (1.0m) going to the highest point (3.0m) and coming back to the lowest point (1.0m). \nDraw a line through where it is 1.5m, which is half way between 1m and 3m. If the whole wave is 12 hours you will see that at a quarter of twelve hours the wave crosses the line you drew for 1.5m.
59019
Tides are periodic rises and falls of large bodies of water. Tides are caused by the gravitational interaction between the Earth and the Moon. The gravitational attraction of the moon causes the oceans to bulge out in the direction of the moon. Another bulge occurs on the opposite side, since the Earth is also being pulled toward the moon (and away from the water on the far side). Since the earth is rotating while this is happening, two tides occur each day. \n\nIsaac Newton (1642 -1727) was the first person to explain tides scientifically. His explanation of the tides (and many other phenomena) was published in 1686, in the second volume of the Principia.
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Hi Izwan, I'm sure you know that the word "tide" refers to the periodic variation in the surface level of the oceans (and of bays, gulfs, inlets, and estuaries), caused by gravitational attraction of the moon and sun.\n\nThe maximum water level is called "high tide" or "high water" and the minimum level is "low tide" or "low water".\n\nThe time between high tide and low tide, when the water level is falling, is called the "ebb". The time between low tide and high tide, when the tide is rising, is called "flow" or "flood". \n\nThe phrase "as the tide was in" refers to the 'flow' or 'flood'\n\nA sample sentence: The ships entered the harbour as the tide was in.\n\nThe word "tide" could also be used to mean "a favorable occasion; an opportunity."\n\nA sample sentence: Sensing the tide was in his favour, the employee asked his boss for a raise, which he got.
16046
some places 24 hours most others 3 days
783260
you might want to be more specific with your question, but it sounds like you're referring to the Red Tide.
1072353
PORTSMOUTH TIDES (heights in parentheses..note Hampton/Seabrook correction below). Note: If you are using Boston Tide Charts when coming to Portsmouth, add 20 minutes to the Portsmouth High Water Values and 17 minutes to the Low.):\n\nHIGH tide: 7:19AM (8.0) and 7:50 PM (8.8). \n\nLOW tide: 1:04 AM (0.3) and 1:23 PM (0.2). \n\nData courtesy www.maineharbors.com <http://www.maineharbors.com>. or
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See if this meets your needs.\n\nhttp://www.fishingworks.com/tide_prediction_interval.cfm