This is the harbor to Plymouth Massachusetts at low tide. Around the world, the oceans levels changes through the day. This change is due to the constant pull of the Moon upon the oceans of Earth as it rotates around it. This causes the level to rise and lower. Around the world this effect is vastly different based upon Latitude, or ones position from the equator. As one gets closer to the North Pole the effects of the tides increases.
Plymouth, Massachusetts rests at 41.95 degrees North. This means the region has significantly high tide activity than say Miami at 25.65 degrees North. This means Plymouth has a variance of over ten feet from low to high tides while Miami has less than three feet difference. The greatest tidal difference is in the Bay of Fundy in Canada at 38.4 feet.
This photo illustrates the depth of the harbor’s tide field by use of Mankind’s greatest measuring stick, Mankind. Since the dawn of civilization, man has used itself to measure and compare to the natural world. This is reflected in the humanistic measurements of feet and hands (still used in the horse industry) and the biblical cubit (based upon the length of a man’s arm from elbow to outstretched fingertips). We innately know the size of the average man and can judge environment it rests in. By showing people at different distances quickly gives a sense of scale to this scene and shows the dramatic change in tides in the northern latitudes.
To learn more about Tides:
http://tidesandcurrents.noaa.gov/
http://en.wikipedia.org/wiki/Tidal_range
To learn about Human Measurement
http://en.wikipedia.org/wiki/History_of_measurement