The study of satellite infrared images and analysis of current measurements in the Strait of Otranto using time and space correlation and power spectra techniques, has shown the existence of a horizontal velocity shear zone, formed between a northward and a southward flowing current. The shear zone extends from the surface to the seabed along an inclined plane. Time and space scales in the northerly and southerly flowing currents are much larger than those in the shear zone. In the unstable flow field of the shear zone, mesoscale eddies and strong near-inertial waves are generated. These advective phenomena seem to be the result of mainly barotropic instability processes. The near-inertial waves are found to be trapped inside the shear zone, and their frequency is found to be affected by the passage of the energy containing eddies and the background flow field vorticity. ¿1991 American Geophysical Union