If you move forward or astern without a rudder, in which direction will the vessel turn when viewed from ahead?

If you move forward or astern without a rudder, in which direction will the vessel turn when viewed from ahead?

• A. Turn clockwise
• B. Turn counterclockwise
• C. Move straight ahead
• D. Turn unpredictably

Answer: (A)

Without a rudder, there’s no sideways force to steer the vessel. The only yawing effect comes from the propeller and the water it drags along the stern. The propeller’s rotation creates a swirl in the flow that pushes the stern to one side, which makes the bow swing to the opposite side. On a typical ship where the propeller rotates clockwise when viewed from astern, that swirl pushes the stern toward port and the bow toward starboard, so from ahead the turn appears clockwise. So, without a rudder, the vessel will turn clockwise.

Without a rudder, there’s no sideways force to steer the vessel. The only yawing effect comes from the propeller and the water it drags along the stern. The propeller’s rotation creates a swirl in the flow that pushes the stern to one side, which makes the bow swing to the opposite side. On a typical ship where the propeller rotates clockwise when viewed from astern, that swirl pushes the stern toward port and the bow toward starboard, so from ahead the turn appears clockwise. So, without a rudder, the vessel will turn clockwise.