🔍 Key Concepts

• Metacentric height (GM) formula using rolling period for a vessel in salt water • Correct use of beam (B) and the constant used with the rolling-period formula • Careful unit handling for seconds and feet, and squaring the rolling period

💭 Think About

• What is the standard formula that relates rolling period (in seconds), beam (in feet), and GM for a ship in salt water? Write it out first. • After you plug in the beam and period, what part of the expression must be squared, and how does that affect the size of GM? • Based on your calculation, which GM value is most reasonable for a 125-foot vessel with a 17-foot beam and a 6-second rolling period: relatively small, moderate, or large?

✅ Before You Answer

• Make sure you are using beam (B = 17 ft) in the correct place in the formula, not length or draft. • Confirm whether the rolling period T is squared in the numerator or denominator of the formula you are using. • After computing GM, compare the magnitude with the choices and ask: Does this GM give a relatively stiff or tender ship, and does that match a 6-second period?