Failure of the means of propulsion, such as engines, sails or rigging, can lead to the loss of a ship. When the ship's movement is determined only by currents or the wind and particularly by storms, a common result is that the ship is unable to avoid natural hazards like rocks, shallow water or tidal races. Loss of propulsion or steering can inhibit a ship's ability to safely position itself in a storm, even far from land. Waves attacking a ship's side can overwhelm and sink it.