This is the curve defined by intersecting a plane diagonally through the bilge area of the hull geometry. The curve can be seen in the profile or plan views. The diagonal plane is defined by two values: its intersection height (Z-value) on centreline and the heel angle of the plane.
Igophe elichazwa ngokudibanisa ipleyini ngokuxwesileyo ngendawo yomphantsi wenqanawe yejiyometri yesiqu senqanawe. Igophe lingabonwa kwiprofayili okanye kwimibono yeplani. Ipleyini exwesileyo ichazwa ngee'valves' ezimbini: ukuphakama kwazo kudibana kumgca osembindini nakwi-engile yokuqethuka kwepleyini.