All seas and oceans of the world have tides. There are exceptions; these are inland seas and the European Mediterranean Sea. Tides are created by the gravitational effects of the moon and sun.
Inland seas have nowhere for the water to flow during these gravitational forces of the moon and sun and therefore exhibit no tidal pull and the water’s edge shows no discernable movement . This is also true of all large lakes and inland waterways. River deltas are, however, subject to tides and tides may be visible up to sixty five miles inland dependant on the width of the river.
The Mediterranean Sea has no tides because sufficient water cannot pass out of the straits of Gibraltar into the Atlantic Ocean fast enough. This is a delight for holiday makers as they do not need to constantly move the deck chairs to compensate for the progression of the tide as it always remains the same.
However, all other seas and oceans of the world have both neap and spring tides and a two week cycle.
A spring tide is caused when the gravitational forces of the sun and moon combine. A spring tide is when the water is at its highest and lowest levels and occurs once a fortnight. The word spring has absolutely nothing to do with the seasons and only demonstrates that the water springs to the shore and after a period springs back.
Spring tides have the most force and as the tide changes one can often hear the waves pick up momentum as the water begins to come into the shore. In very shallow waters, the tide can come in alarmingly quickly. A few years ago, some Chinese cockle pickers lost their lives in Morecombe Bay, England, during a spring tide. They were unprepared for the tide to change so rapidly and they died because they could not return to the shore quickly enough to save themselves from drowning.
A neap tide occurs in between the spring tides about a week after the tide was at its height and the sun and moon are at right angles to each other. This causes the least gravitational pull and the tidal flow in and out from the shore is at its minimal. This period is often the best time for anglers to fish as fish feed more readily when there is less pull on the sea.