Castle

It is full tide.
Slowly the water starts to ebb away, revealing some sand.
Some kids pounce on it, declaring, "Castle!"
they work frantically as the tide goes out, and comes back in, intermitently encouraging their frenzy with "Castle!"
The tide gets closer, they work even more frantically, if possible "Castle!"
They have built the biggest most elaborate sand castle imaginable!
Yet they still work on it to try to secure it, as the tide laps at it "Castle!"
As the tide starts to erode it away, they try to rebuild it, and to make elaborate water systems and walls to keep the tide back. "Castle!" they call to each other frantically! No other words are needed. The task is known, and they are determined.
Throughout their frantic work, the tide is ever persistant.
Slowly but surely, the tide covers their work, constantly rounding the edges and collapsing the sides.
a child stands on the underwater mound that was the castle to mark the spot, as another hauls buckets of sand and dumps them on the ever decreasing pile. She stands on driftwood and seaweed they mix in the lump in hopes that it won't all wash away. They take turns standing in the cold water protecting the castle with their bodies as the other brings more stuff, or warms up by a beach fire, snuggles in a towel, or sips something hot. All the while, still completely excited and yelling "Castle!" to hype each other up!
Finally the tide starts to ebb again. They still work frantically!
The water finally reveals a small lump of sand, with random seaweed and driftwood sticking out of it. "Castle!" they all cry triumphant! and start to build it again.
(it would be nice if the time of day was shown by sunrise and sunset, etc.)