Abstract: A swimmer's aid including a strip to which a plurality of laterally extending finlets are attached with the strip being attachable to one or more portions of a swimmer's leg e.g. his shank or his foot, or both. The fins flex in directions opposite to the kick of a swimmer's legs in a manner similar to a conventional foot fin but their center of effort is located closer to the stronger parts of a swimmer's legs rather than only at their extremities as with conventional foot fins. The invention includes a short downwardly angled foot fin having a permanent but shallow angle of about 15.degree. relative to the plane of the foot to permit walking on dry ground while requiring less effort to use in the water.