We are all drifters on the sea of time, from the moment we are born.
The only hope is the far off land in the distance, tempting, vague.
But the tide is always against us. The water is perpetually flowing toward the opposite direction.
Sooner or later, when one becomes old, worn out, or lose his/her hope, he/she doesn't have enough strength to fight the water anymore. The current will carry the boat backward with it. The 'down hill' of life starts.
Till the end, the water gushing off the water fall, with the beaten boats, into oblivion.
This is a metaphor of life, the constant struggles and enjoyments, successes and failures, of human story.