Abstract : This work was focused on the dynamics of stratified flow in sea straits, primarily the Bab al Mandab (BAM). Possible hydraulic control of the exchange flow in the BAM was investigated by analyzing data collected by Drs. Steve Murray and Bill Johns as part of a recent 2-year field program The analysis centered on the calculation of long wave speeds for the first and second baroclinic modes of the stratified shear flows at the sill and narrowest section of the Strait. Doing so required advancements in the theory of internal long waves in straits with nonuniform cross-channel topography. The hydraulic character of the flow is vital in the understanding of the stratification in the BAM and in the neighboring Red Sea and Gulf of Aden. Theoretical studies of the effects of rotation on hydraulically controlled flows in straits were also carried out. The results reveal some remarkable structural features such as transverse hydraulic jumps, recirculations and splitting of the flow.