On a steeply sloping beach - usually pebbles - high water mark and low water mark are close together. On a gently sloping beach (usually a sandy one) high water mark and low water mark are far apart. This often exposes, or uncovers, a wide area of sand and mud. The sea is 'a long way out' at low tide!

The difference between water level at high and low tide can sometimes be seen directly on vertical cliffs.