The greatest tide change on earth occurs in the Bay of Fundy. The difference between low tide and high tide can be as great as 54 ft. 6 in. (16.6 meters).
The highest tides in the world can be found in Canada at the Bay of Fundy, which separates New Brunswick from Nova Scotia.
The highest tides in the United States can be found near Anchorage, Alaska, with tidal ranges up to 40 feet.
Tidal highs and lows depending on a lot of different factors. The shape and geometry of a coastline play a major role, as do the locations of the Sun and Moon. Storm systems at sea and on land also shift large quantities of water around and affect the tides. Detailed forecasts are available for high and low tides in all seaports, but are specific to local conditions.
That many of the areas of the world with high ranges of tides are in the areas of Alaska, Canada, and northern Europe has created a misconception that the range of tide increases with increasing latitude (as one moves farther from the equator and closer to the poles). This is incorrect.
Increased tidal ranges in these areas are created by the positions and configurations of the continents in the northern hemisphere. In the higher latitudes of the northern hemisphere, the continents of North America, Europe, and Asia are pressed closer together. This "constriction" of the oceans creates the effect of a higher range of tides.
In the higher latitudes of the southern hemisphere, in the southern tips of South America, southern Africa, Australia, and Antarctica, tidal ranges are not increased. In these areas the continents are not pressed closely together, there is not a "constriction" of the oceans, and the tidal ranges are not increased.