🔍 Key Concepts

• Relationship between forward perpendicular (FP) and after perpendicular (AP) • The term naval architects use for the longitudinal midpoint of a vessel used as a reference in plans and calculations • Difference between center line (side‑to‑side reference) and the mid-length point (bow‑to‑stern reference)

💭 Think About

• Which choice specifically refers to the point halfway along the ship’s length between FP and AP, used as a reference in design drawings and stability calculations? • Which option is a general geometric term for the vessel’s symmetry plane, and not a point located halfway between the perpendiculars? • Which term is commonly used to describe the central region or section of a hull, rather than a single reference point on the length?

✅ Before You Answer

• Identify which option names a single point along the length (bow to stern), not an entire region or plane • Distinguish between transverse reference (side-to-side symmetry plane) and longitudinal reference (lengthwise midpoint) • Recall naval architecture terminology: which term appears on lines plans and construction drawings at the mid-length between FP and AP?