This section gives a brief description of the various values that are determined by Hydromax in the evaluation of criteria.

There are two distinct types of criteria:

Equilibrium criteria

Equilibrium criteria are evaluated after an Equilibrium analysis and refer only to the condition of the vessel in its equilibrium state For example: margin line immersion tests, freeboard measurements, trim angle, metacentric height, etc. This type of criterion is also used by the Floodable Length analysis. Equilibrium criteria can be recognised by the  icon.

Criteria derived from measurements of the GZ curve.

These are calculated after a Large Angle Stability analysis and during a Limiting KG analysis. For example, area under GZ curve between specified limits, angle of maximum GZ, etc. These criteria are often referred to as Large Angle Stability (LAS) or GZ criteria.

Note:

The metacentre is always (even for Large Angle Stability criteria) computed directly from the vessel’s hydrostatic properties (i.e. water-plane inertia and immersed volume) at the specified heel angle and not from the slope of the GZ curve. This gives an accurate result that is not dependent on the heel angles and intervals tested during the analysis.