Steve Braden, age 10, of Eugene, Ore.,For his question;

Is sea level measured when the tide is in or out?

The 1evel of the sea changes with every tide. The winds and the sweeping currents also pue up high mountains of water at the surface of the sea. Sea level then is different in different places and at different times. However, we measure the height of the bumpy land in feet above sea level.

This sea level is a standard measurement taken from countless parts of the ocean. It is the halfway mark between high tides and low tides. We call it the mean or average Sea level. Taking this average figure as a standard, We can say that Mt. Whitney of California is 11,495 feet above sea level and that Death Val1ey, a short distance to the southeast, is 282 feet below Sea level.