Angle of Vanishing Stability
Heel angle at which the GZ righting arm becomes zero — beyond which the ship will capsize.
In practice
Read off the GZ curve at every loading condition. Less than 60° in normal voyage condition triggers loading-plan review.
Regulatory detail & full definition
Heel angle at which the GZ righting arm becomes zero — beyond this angle the ship will not return to upright but will continue heeling and capsize. The 2008 IS Code requires the angle of vanishing stability to be at least 60° in normal conditions (40° in some restricted-service ship types). The angle is read from the GZ curve and is sensitive to deck-edge immersion and downflooding through openings. Loading conditions producing reduced angles of vanishing stability are typically rejected at the loading-manual approval stage.
Authoritative source: 2008 IS Code ↗
Related
Source: 2008 IS Code
High confidence
Editorial confidence: how we grade.