The application relates to water craft hulls having improved hydrodynamic stability. A hull (1) is claimed in which the center of gravity (C_g) is substantially vertically aligned with the center of hydrodynamic lift (C_p) of a lifting surface of the hull, both at lift-off speed and at design speed, and preferably also at speeds below lift-off, and at all speeds between lift-off and design speed and above. A hull having a relatively high aspect ratio at design speed, and preferably also at lift-off speed, is also claimed. In the preferred embodiment, the hull is generally delta-shaped in plan view.