"CA oil spill: Evidence suggests anchor snagged pipeline...The pipe was split open and a nearly mile-long section apparently pulled along the ocean floor, possibly by "an anchor that hooked the pipeline, causing a partial tear," ...Even when anchored, cargo ships continually move from shifting winds and tides. If a ship fails to properly set its anchor in the ocean floor, those forces of nature come into play and can push the ship and drag the anchor along the bottom, potentially catching anything in its way, .."
