Currents of Time

How nothing seems to change, but does - or the vice versa.

In these currents of time
Are you rock, sand or tide?
Sound of news will chime
As on waves they will ride

The water may storm, and will
Take sand away with force
After frothing waves, comes still
As ever, tide keeps it's course

Then the new waters came
But always saw the rock humble:
The shore is still the same
And too easily won't crumble