Nordsjøen (North Sea)
Vase planted by Inge Bjart Torkildsen and Alf Torbjorn Rob, June 18, 2013

“We took a personal cabin cruiser boat 3 nautical miles offshore from Hidra Island, just south of Flekkefjord and dropped the vase, which had been cemented in heavy concrete, into a muddy sea bed, 230 meters deep, so it should be well-grounded.”