🔍 Key Concepts
• Six degrees of freedom of ship motion (surge, sway, heave, roll, pitch, yaw)
• Difference between translational (straight-line) motion and rotational (rocking/turning) motion
• Meaning of fore-and-aft versus athwartships (side-to-side) directions on a vessel
💭 Think About
• First decide: is the question asking about a straight-line shift or a rocking/rotating motion of the vessel?
• Think about which motions are rotations about an axis (like see-saw or rocking chair) and which are sliding motions along a direction.
• Match each option (pitch, surge, sway, roll) to the type of motion and direction it describes (up/down, fore-and-aft, side-to-side, rotation about length or width).
✅ Before You Answer
• Identify which terms describe rotational motions (rocking) versus linear motions (sliding).
• Confirm which ship direction is fore-and-aft (bow to stern) and which is athwartships (port to starboard).
• From the remaining choices, verify which specific term means a straight-line horizontal movement in the fore-and-aft direction.