From October 1977 through November 1980 a current-meter mooring was maintained in the Yucatan Strait. The meter was moored halfway between Mexico and Cuba. 145 m above the sill or in 1895 m of water. Motions of low frequency (<14-1 cycles/day) are oriented approximately parallel to the isobaths. 021¿--030¿ true. Net drift for 3 years is to the SSW at an average velocity of 1.8 cm/s. Sustained southward flows at intervals of 8 months, which persisted for several months each, have average velocities of 5 cm/s, with randomly spaced bursts as high as 15 cm/s. Energy in subtidal frequency bands has significant peaks near 38-1 and 19-1 cycles/day, with a broad band of energy between 300-1 and 200-1 cycles/day. The latter peak is consistent with the approximately 8-month interval between the southward flow events. Comparison with weekly areal coverage of the Gulf Loop Current from Geostationary Operational Environmental Satellite infrared observations show little covariation, except that 8 months is typical of some anticyclonic eddy generation. There is little coherence of sill depth velocities with Naples sea level at subtidal frequencies, but with Miami there is coherence at several frequencies, notably 38-1 and 19-1 cycles/day. In the higher frequencies, the principal tidal motions are diurnal and are oriented somewhat across the isobaths toward the northwest, 346¿--349¿ true, with counterrotating O1 and K1 constituents. No semidiurnal inertial, or fortnightly energy is observed above the background continuum.