🔍 Key Concepts

• GM (metacentric height) and what it tells you about a vessel’s initial stability • The effect of transverse center of gravity (TCG) on whether a vessel sits upright or with a permanent list • How ballast and deck load mainly affect KG (vertical center of gravity) and displacement

💭 Think About

• Ask yourself: what specific stability condition makes a vessel unable to remain upright, so it must lean to one side or the other? • Which term (GM or TCG) is primarily about how stable the vessel is, and which is about which way it will lean? • For a semisubmersible, what happens if the righting arm (GZ) is zero or negative at very small angles of heel?

✅ Before You Answer

• Identify which choice refers to initial stability (how the vessel reacts to a very small heel angle). • Identify which choice refers to the off-center location of G (center of gravity) sideways, causing a list. • Before choosing, be sure you know whether a vessel that cannot stay upright is more directly linked to negative GM or to large TCG.