The largest tidal ranges in the world occur in the Bay of Fundy
(more exactly Minas Basin) and in Ungava Bay
(more exactly Leaf Basin) on the East Coast of Canada
, where you can observe a 16 to 17 metre
(53 - 56 foot) tidal range
Tidal ranges in the Bay of Fundy and Ungava Bay are the highest in the world because of an unusual combination of resonance (or seiche) and the shape of the bay
The Bay of Fundy and Ungava Bay are "V" shaped, so that water
entering at their wide mouth at the open ocean end is funneled into less and less space as it moves into the head
of the bays and the water can only pile up and form a large tide.
The water in the Bay of Fundy and Ungava Bay also has a natural rocking motion called a seiche. You could compare this to the movement of water in a bathtub. Although the water in a bathtub sloshes from one end to the other and back again in a few seconds, it takes about 13 hours for the water in the bays to rock from the mouth of the bays to the head
of the bays and back again. The Atlantic ocean
tide rising and flooding into the bay every 12 hours and 25 minutes reinforces the rocking motion. The seiche in the Bay of Fundy and Ungava Bay are therefore sustained by a pulse from the ocean tides.
Other places in the world have large tides: the Port of Bristol in England
(10 m, 33'); the Sea of Okhotsk northeast of Japan
(10 m); Turnagain Arm in Alaska
(12 m, 38'); the Gulf of St. Malo in France
(14 m, 46').