Examining Intimate96 hydrophone data (300 to 800 Hz) we see clearly the effects of tidal changes, i.e., of changing water depths. In this work we will examine Matched Field Processing (MFP) sensitivity at that range of frequencies to expected tidal changes (the depth varies ±1.0 m from the nominal of 135 m). Is it possible to invert such data to accurately and uniquely estimate water depth D as a function of time (tides)? What about accurate, unique, simultaneous estimates of source range rsou? What happens when we use multiple frequencies and when D is known to shift in a predictable fashion? Can the rsou vs D ambiguity ever be resolved for a successful, unique MFP inversion for those parameters?