This book describes a mathematical model of flow past a lifting system performing steady and unsteady motion in close proximity to the underlying solid surface (ground). The author considers various approximations based on the general method of matched asymptotic expansions applied to lifting flows. Particular importance is attached to the case of extreme ground effects describing very small relative ground clearances. Practitioners involved in the design of wing-in-ground effect vehicles will find in this book all the relevant formulae and calculated data for the prediction of aerodynamic characteristics in this important limiting case. More generally, this book is suitable for graduate students, researchers and engineers working or lecturing in the area of theoretical aerodynamics.