Japanese glass floats, K'gari (Fraser Island)

Glass floats, glass fishing floats, or Japanese glass fishing floats are popular collectors' items. They were once used by fishermen in many parts of the world to keep their fishing nets, as well as longlines or droplines, afloat.

Large groups of fishnets strung together, sometimes 50 miles (80 km) long, were set adrift in the ocean and supported near the surface by hollow glass balls or cylinders containing air to give them buoyancy. These glass floats are no longer used by fishermen, but many of them are still afloat in the world's oceans, primarily the Pacific. They have become a popular collectors' item for beachcombers and decorators. Replicas are now manufactured. (Wikipedia)