Erratum: “Low Cost Measurements of Shoreline Change” by Robert M. Clancy, Fred E. Camfield, and Christine Schneider at the ASCE Specialty Conference on the Design, Construction, Maintenance and Performance of Coastal Structures, Arlington, Va., March 9–11, 1983, and published in <i>Coastal Structures '83</i>, by ASCE, New York, N.Y., 1983, 1012 pp