the horizontal speed of water due to tidal influence is based on aeons of observations at the location under question. Ocean Inlets, major canals, etc. all where the speed of the water can be a problem can be obtained from 'almanacs', or from computer tide programs --- if your have a macintosh, "Mr. Tides3" is a good 'shareware' program. For vertical movement the maximum 'movement' occurs halfway between the high and low tides and can be estimated based on generalized formulas from those almanacs. For small bays, etc. separated from large bodies of water by landmass restrictions, there is usually some 'lag time' of the tides vertical filling and draining caused by restrictions in the 'connecting chanels' and inlets, etc.
