A coherent pulse Doppler sonar with a few centimeters range resolution provides effective monitoring of slow water velocity with excellent resolution. The experiments presented in the paper were conducted with a sonar transducer resting on the floor of a waterway influenced by tidal effects with the transducer producing a beam tilted from the horizontal. All the results are shown in the form of Doppler Spectra composed of radial velocity estimates separated by a few mm/s, which are presented at adjacent range gates spaced by 4.5 or 9 cm, so that a vertical profile of horizontal velocity extending from the waterway bottom to the water surface is derived from the data. Continuous monitoring of these profiles shows considerable detail in the evolution of the ebb/flood characteristics of the flow during tidal cycles.