Here's some awesome shots from NASA's Goddard Space Flight Center showing the intricate puzzle of seaweed farms in South Korea. The sea fields of seaweed are grown on ropes strung along the southern coast of South Korea around Sisan Island. It makes for a beautiful image when seen from afar.
The dark squares that make up the checkerboard pattern in this image are fields of a sort — fields of seaweed. Along the south coast of South Korea, seaweed is often grown on ropes, which are held near the surface with buoys. This technique ensures that the seaweed stays close enough to the surface to get enough light during high tide but doesn't scrape against the bottom during low tide.
And the full image: