Naturalbeachestendtobeconcave-upratherthanplanarandarereasonabletobemodeledbyanequilibriumbeachprofile.Agoverningequationforlongshorecurrentonanequilibriumbeachisderivedanditsanalyticalsolutionisgiveninthispaper.Throughcomparisonsofthepresentsolutionandfielddataoflongshorecurrentforastep-typebeach,thepresentsolutionisfoundtohavefairlyagreeablepredictiontolongshorecurrentinsidethesurfzone.Theeffectsoftheshapeofaconcave-upbeachandturbulentmixingstressonlongshorecurrentinsidethesurfzonearediscussedinthepresentpaper.
