Question 3880 Deck General

The correct answer is C) over 3 knots headway. The bow thruster is generally ineffective at speeds over 3 knots of headway (forward movement) because at higher speeds, the flow of water over the bow creates a force that overcomes the thrusters' ability to generate sufficient side force to effectively maneuver the vessel. The bow thruster is designed to assist with low-speed maneuvering, particularly for docking and undocking operations, but its effectiveness diminishes as the vessel's speed increases. The other answer choices are incorrect because: A) the bow thruster can still be effective at over 1 knot of sternway (backward movement), B) the bow thruster is effective at some speeds ahead, and D) the bow thruster can still be effective at some speeds astern (backward movement).