What are Spring and Neap tides?

Very high tide is caused when the sun, the moon and the earth are almost in the same line. Such high tides are called spring tides.

On the seventh or eighth day of every fortnight of a month, the sun, the earth and the moon come in the position of quadrature. The tide producing forces of the sun and the moon work in opposite direction, with the result, a low tide occurs. Such a tide, which is lower in height than that of a normal tide, is called neap tide.