🔍 Key Concepts
• Degrees of freedom of a vessel’s motion (surge, sway, heave, roll, pitch, yaw)
• Difference between motion along an axis (fore‑and‑aft, athwartships, vertical) and rotation about an axis
• Standard terminology for horizontal sideways motion versus turning motion
💭 Think About
• First, sort the options into motions that are up‑and‑down, forward‑and‑aft, sideways, or rotational. Which ones are linear motions and which are rotations?
• Ask yourself: which term describes the ship sliding sideways to port or starboard without the bow swinging around?
• Eliminate any terms that clearly refer to vertical motion or to the bow swinging left and right about a vertical axis.
✅ Before You Answer
• Be clear which axis is fore‑and‑aft (longitudinal), which is athwartships (side‑to‑side), and which is vertical.
• Identify which listed motions are rotations about an axis (not the right choice here).
• Confirm which single term is defined as lateral (port/starboard) translation of the vessel’s center of gravity.