Variability of the Florida Current has been monitored via acoustic tomography. A reciprocal tomography experiment was conducted in the eastern half of the Florida Straits during mid-October and November, 1983. A triangular array of transceivers, with leg separations of approximately 45 km, was deployed at 27 ¿N. The presence of a surface mixed layer in the region allowed for the ducted propagation of acoustic energy in the surface layer. A deeper layer was sampled by an unresolved group of refracted, bottom-reflected ray arrivals. Incorporating the complete set of arrivals, we are able to obtain depth-dependent estimates of the temperature field, current velocity, and relative vorticity. The oceanography of the region has been shown to be dominated by the lateral shifting of the surface and subsurface core of the Florida Current. The influx of westward flowing water through the Northwest Providence Channel at 26 ¿N also appears as a large-scale signal in the eastern Florida Straits. Low-frequency fluctuations of temperature, current velocity, and vorticity occur at periods ranging from several days to nearly 2 weeks, and are intimately related to meandering of the Florida Current system. ¿ American Geophysical Union 1991