As a novel approach to computing the flux of tidal power into shelf areas, tidal maps of an oceanic area near the Patagonian Shelf are derived from 11 months of altimetry records from the GEOSAT satellites. Power fluxes are computed from the maps through Laplace's tidal equations. Flux vectors for M2 clearly show a covergence on to the southern portion of the shelf sea and their total is nearly twice the loss computed by Miller for the area. A decrease of 'quality factor' with frequently from M2 to S2 is in keeping with Webb's hypothesis of shelf resonances at frequencies a little higher than the tidal band. ¿ American Geophysical Union 1989