🔍 Key Concepts

• Six degrees of freedom of vessel motion (surge, sway, heave, roll, pitch, yaw) • Difference between linear (translational) motion and rotational motion • Meaning of fore-and-aft vs athwartships directions on a vessel

💭 Think About

• First, decide: is the question asking about a motion that is straight-line (back-and-forth) or a rotational/tilting motion? • Match each option to its type of motion: which ones are rotations, and which ones are side-to-side, up-and-down, or forward-and-back? • Remember which axis runs bow to stern and which motions happen around that axis versus along that axis.

✅ Before You Answer

• Identify which choices describe rotational motion (tilting about an axis) and remove them if the question asks for straight-line motion. • Check which term is used for motion along the fore-and-aft axis (toward bow or stern) rather than sideways. • Verify that the term you choose is associated with horizontal movement, not vertical up-and-down motion.