The tide differences is caused by the gravitation from the sun and the moon and the centrifugal powers on the turning earth. These powers cause a rise of the sea level both on the part of the earth that is facing towards and against the moon. That results in a change between a high tide and a low tide in a period of 12 hours and 25 minutes. A companionship between the sun and the moon causes a change between maximum and minimum tide difference in a period of 14 days. Topographical conditions also have an impact on the tide differences. The speed of tidal waters varies after the deterrents it meets.