Tidal currents in Botany Bay and its rivers have been examined to to assess tidal action and the effect on water movement of dredging works. Data are derived from collections and models, and the probable effects of further work is estimated. Volume 1 (paper) describes the methods , data summary and discussion. Microfiche (3) Appendix A, Prtotype data. Volume 2 pdf files. Appendix b c-d pdf files contain detailed data.