Ithink it is the Moon's gravitational pull .
sea shore
High tides, low tides, spring tides (which are maximum high tides) and neap tides (which are the lowest of low tides).
Fifteen thousand feet.
They consider high and low tides in their journey because if it is high tide the water level will be high but if it is low tides the water level is low.
Low tides
It varies from day to day and from place to place. It is dependant upon where the Moon and Sun are in relationship to the Earth and the specific location. There are tide tables available that will give the times in key locations with directions on how to determine the difference for areas nearby. Most communities will publish the time of high and low tides in the local paper.
Tides that are not very high and not very low are called neap tides.
High tides. The others are called low tides.
Actually, there are TWO high tides and TWO low tides, on almost every day.
medium tides
Extra high tides are called spring tides and extra low tides are called neap tides ********************************************* Spring high tide is a tide that is very high and reaches high up the beach. Spring low tide is a tide that is very low and goes far down the beach. Neap tides are the high and low water tides that range over the beach between the Spring tide marks.
same