The Calculate Areas function in the Data menu allows the area of surfaces to be accurately calculated, together with their longitudinal, transverse and vertical centre of gravity. The dialog also includes the surfaces' second moments of area about their centres of area. This can be useful when estimating gyradii of the designs.

It is possible to compute the total, above water or below water area and inertias. The values account for trimming and surface symmetry. The DWL, as defined by the Frame of Reference, is used.

A fine mesh triangulation of the surface is used, so errors inherent in the use of Simpson's rule are avoided. The higher the precision selected, the denser the triangulation, and the more accurate the answer will be. The CG positions are given relative to the current zero point.

The projected transverse areas and centroids may also be computed, and this is useful for estimating centres of pressures. Note that the total projected area is computed, so if you have a propeller tunnel for example, both sides of the tunnel will be included.

It is important to distinguish between the CG of the surface area and the centre of lateral area provided by the Calculations window. In the first case the centre is of the entire 3D area, whereas in the second case the centre is of the 2D projection of the area.

It is possible to copy the columns of data from the dialog by clicking and dragging over the cells you require and then using the Ctrl C Copy command to copy the data to the clipboard.

Click the Finish button when you wish to close the dialog.