The final role play

The plank which holds the sea water,
is a ladder, unto which we walk,
When the tide reaches the sky, We float.
The tide ebbs, nurturing like a mother,
We source all life from within,
If ever there was a legend,
I would call it salt,
For if salt loses its saltiness,
What worth would it possess?
Life giving and taking,
Seems like chess.
And I wish not to take thee for granted,
But when my will sinks,
I try to be the plank.