Hydrostatic curves

Hydrostatic curves are the plotted properties of the upright hull as functions of draft: displacement, TPC, MCT1cm, KB, BM, KM, LCB, and LCF. The terms hydrostatic curves and curves of form are used interchangeably. They come from integrating the section areas at each waterline, typically by Simpson’s rule, for the design trim. A naval architect reads them at the operating draft to assemble a trim and stability calculation, then corrects for actual KG and free surface. They cover only small-angle, upright flotation; large-angle righting arms come from the separate cross-curves of stability. They are computed for seawater 1.025 t per cubic meter, with density corrections applied as needed.