Air cushion vehicles are divided into two different categories, those
supported by a self-generated cushion of air [aerostatic] and those upon
forward speed to develop lift, like an aeroplane [aerodynamic].
Aerostatic types - self-generated cushion of air
Captured air bubble
Trunked annular jet
Here, the cushion is put down under pressure by a fan or fans and
contained beneath the hull by flexible skirts or by rigid sidewalls.
Aerodynamic types - lift developed by forward speed