Yawing: Yawing involves rotation of the ship around its vertical axis. This occurs due to the impossibility of steering a ship on an absolutely straight course. Depending upon sea conditions and rudder deflection, the ship will swing around its projected course. Yawing is not a cause of shipping damage.
A yaw rotation is a movement around the yaw axis of a rigid body that changes the direction it is pointing, to the left or right of its direction of motion.
In a strong wind, the vessel will tend to yaw about her heading. At the extremity of her yaw vessel surges ahead and then drops back on her anchor, jerking the cable. If during the yaw the wind catches her on the opposite side to that normally exposed to her natural sheer, she may at the extremity of her yaw, surge rapidly across her anchor to the other extremity of yaw, nipping her cable round the stem and breaking the anchor out of its holding position. This is called breaking sheer, if the anchor fails to re-trip, the other anchor be let go at once.