If there was ever a truer tide clock then this is it. This stubborn and sturdy little piece of seaweed has been marking the ebb and flow of the tide against this rock. Over time it has gently etched the symbolic circle of time. The forces of rock and water have worked against this seaweed time and time again and yet this fragile little plant has stuck in there and used those very forces to make its mark. There is a moral in there somewhere.