What is effect of wind on Ship Manoeuvring or Motion ?

Head Wind

A wind-force of 25 knots exerts a longitudi­nal force of about 6 tons on a tanker of 70,000 dwt in ballast. A long as the ship is heading right into the wind, there is no transverse component of the wind-force. When the ship is moving ahead through the water, we have good steering control with the pivot point forward.

Under sternway, the ship is in ail unsta­ble equilibrium with the pivot point aft. If a transverse wind-force develops, a long distance to the pivot point and consequently much leverage is created. Since the rudder has very little effect under sternway,

we depend on a forward tug or on a bow thruster to keep the ship under control.