A positive number is called a complete stability certificate
A supplied small-angle classroom model gives KM and KG, vessel displacement and a slack rectangular tank with an unrestricted free surface. A learner subtracts the corresponding correction and obtains a positive effective GM, then claims the vessel meets every intact and damaged stability requirement in every sea state. The exercise supplies no righting-arm curve, downflooding condition, asymmetrical flooding case, approved loading booklet or validated operational loading plan. Another student applies the same rectangular formula at a large heel where the free surface would be clipped by the tank boundary. The teacher asks which mathematical conclusion is supported and why the wider compliance and geometry claims do not follow.
1. What is the best supported engineering conclusion?
Read the worked answer
A positive corrected initial GM is only one bounded result; complete criteria and valid geometry require their actual approved assessment.
2. What actual competence or evidence is still required?
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The relevant model limits, equipment and vessel information, qualified assessment and applicable current requirements still govern. Written recognition does not authorize an actual operational change.