We use a sequence of synthetic aperture radar (SAR) images to map differences in the flood and ebb tidal currents in a cove along the coast of Nova Scotia, Canada. The asymmetry in the tidal flow determines the flushing rate of the cove which, in turn, has a significant effect on biological production within the cove and its potential for aquaculture. We find significant differences in the SAR images collected on flood and ebb tides. Specifically there are well-defined lines on the flood images and large whorls on the ebb. A three-dimensional hydrodynamic model of the tidal currents is used to interpret the SAR images. In particular we use the model flow fields to wind back the SAR images to an earlier stage of the tide in an attempt to determine the physical origin of the features in the images. We conclude that the most likely explanation for the ebb-tide whorls is the advection of surface slicks.