Cable laying vessels are vessels used to lay underwater cables. Besides laying new cables, they can also find and repair broken or damaged cables at sea. To protect the cables, they are sometimes buried in the seabed using a special plough, especially in deep water or areas where damage is likely. These vessels have a dynamic positioning system (DP2) that helps them stay exactly in the right spot above the cable route. They are equipped with strong engines and a positioning system to stay steady. The cable is stored in a spiral on a rotating carousel and is unrolled smoothly as it is laid. The biggest cable laying ships can carry over 10,000 tons of cable on board.