The tides are the regular rise and fall of the ocean . They are seen most prominently along coasts and in harbors and bays .
Tides occur in all bodies of water.
In small, enclosed areas such as lakes and ponds, however, the rise and fall of the water are slight and usually pass unnoticed. Where the oceans meet the land along seacoasts and in bays and harbours , the tides are more prominent. In mid-ocean the difference between high water and low water is perhaps two or three feet. Along the shores of continents, especially in gradually narrowing bays, the difference may be much greater. In most places, the tide rises and falls twice a day, reaching a maximum height called high tide on each rise and a minimum level called low tide on each fall.