The Mellor and Yamada (1974) Level II turbulence closure scheme is used to study the oceanic bottom boundary layer (BBL). The model is tested against observations of the BBL obtained on the western Florida Shelf reported in Weatherly and Van Leer (1977) and in turn conclusions about the BBL made in that paper are tested against the model. The agreement between the model and the observations is good. The predicted and observed BBL thickness is ∼10 m which is appreciably less than 0.4 u*/f ≈ 30 m, where u* is the friction velocity and f the Coriolis parameter. The reason for the discrepancy is attributed to the BBL being formed in water which initially was stably stratified and characterized by a Brunt Vasäilä frequency N0. It is suggested that the oceanic BBL thickness should be identified with the height at which the turbulence generated in the BBL goes to zero and on dimensional grounds it is proposed that this thickness is A u*/f(1 + N02/f2)½, where A is a constant. The Level II model indicates... Abstract The Mellor and Yamada (1974) Level II turbulence closure scheme is used to study the oceanic bottom boundary layer (BBL). The model is tested against observations of the BBL obtained on the western Florida Shelf reported in Weatherly and Van Leer (1977) and in turn conclusions about the BBL made in that paper are tested against the model. The agreement between the model and the observations is good. The predicted and observed BBL thickness is ∼10 m which is appreciably less than 0.4 u*/f ≈ 30 m, where u* is the friction velocity and f the Coriolis parameter. The reason for the discrepancy is attributed to the BBL being formed in water which initially was stably stratified and characterized by a Brunt Vasäilä frequency N0. It is suggested that the oceanic BBL thickness should be identified with the height at which the turbulence generated in the BBL goes to zero and on dimensional grounds it is proposed that this thickness is A u*/f(1 + N02/f2)½, where A is a constant. The Level II model indicates...