The astronomic tidal circulation in Puget Sound, Washington, is investigated using the Waterways Implicit Flooding Model (WIFM) in two-dimensional, vertically-averaged context. The state of knowledge of general circulation characteristics is presented as a prelude to the numerical modeling investigation. A general tide prediction program had been developed which predicts both tidal evaluations and horizontal currents. Astronomic tidal characteristics are studied on a 70 (horizontal) by 103 (vertical) dimension global grid comprising 7,210 cells with a maximum spatial resolution of 3,750 ft. A 90-sec time-step was employed in all WIFM long-wave simulations resulting in a maximum Courant number of 4.1. Simulated tidal elevations and vertically-averaged currents were calibrated to predicted values for the 16-18 January 1981 spring tide period. Calibrated bottom friction mechanics were verified using the 13-15 January 1981 neap tide period. Simulated results corresponded to predicted values of elevation and current except for some discrepancies in the Southern Basin. Peak current magnitudes were tabulated at existing disposal sites for both calibration and verification of astronomic tide conditions. Meteorological effects and freshwater inflows were not considered. The 11-13 December 1985 extreme spring tide period was also simulated, and maximum current velocities and their associated times of occurrence were tabulated. Keywords: Finite difference method; Hydrodynamics; Mathematical models; Dredge disposal.