Use the material in Section 1, the blue pages, of the Stability Data Reference Book. If the KG is 24.0 feet, and the drafts are: FWD 28'-01", AFT 28'-06"; at what angle will the vessel lose positive stability?

Correct Answer: Option B — 71°

Entering the stability data reference book with the mean draft and given KG of 24.0 feet allows cross-referencing the cross curves of stability (KN curves) to locate the vanishing angle of stability at 71 degrees where the righting arm (GZ) becomes zero.