Intact Stability

Intact stability assesses the righting characteristics of an undamaged ship under the 2008 Intact Stability Code, made mandatory through SOLAS II-1 and the Load Line Convention. Part A sets criteria all ships must meet: minimum metacentric height, minimum area under the GZ curve to 30 and 40 degrees, maximum righting arm at or beyond 25 to 30 degrees, and a severe-wind-and-rolling weather criterion. Part B adds recommendations for specific ship types. The calculations rely on hydrostatics, the position of the center of gravity, and free surface corrections for slack tanks.