🔍 Key Concepts

• Righting arm (GZ) and how it relates to the righting moment • What it means for a vessel or unit to be "level in calm water" (i.e., angle of heel) • The formula: Righting moment = displacement × GZ

💭 Think About

• If the unit is perfectly upright in calm water, what is the angle of heel? How does that affect the righting arm GZ? • Think about the stability curve: at exactly 0° heel, what is the value of GZ for a typical stable vessel? • If GZ is at that value, what does that do to the righting moment when you multiply by the displacement?

✅ Before You Answer

• Confirm what GZ equals at 0° heel for a stable, upright vessel • Check whether the question provides any GZ value or displacement to actually compute a numerical righting moment • Ask yourself: if the unit is perfectly upright with no heel and no disturbing force, is there any leverage to create a righting couple?