'draw a line in the sand',
well here is an artist that actually does just that,
using the sand on a beach as his canvas,
California artist Jim Denevan, has made his mark in the sand, etching elaborate geometric artworks on beaches around the world,
the pieces last only a few hours, or begin disappearing even as he works, as the tides quickly erase each design leaving only a memory or a photograph, and listening to the video here is the neat thing, although he some times uses brought tool such as rakes, the best experience for him is to arrive with nothing and leave with nothing, he uses found pieces of stick or driftwood to create his works that are then swept clean by the incoming tide, and some of his works are huge if you watch the video and all are carried around in his head with as far as I can tell no template to work from!