It has been long known by Australian meteorologists that a nocturnal jet is a frequent feature of the low-level wind profile at Daly Waters in the Northern Territory of Australia. The Koorin Expedition during the southern winter of 1974 obtained data on wind and temperature profiles in the boundary layer which form an ideal base for the study of this phenomenon. In this paper, a simple model of the jet is described and the results of the model are compared with observations. The model is essentially a development of the pioneering work of Blackadar, who proposed that a low-level jet could develop as an inertial oscillation. The observations do show some of the features of the model.