Quality-control of bottom pressure based sea level gauge has been effected using a statistically derived simple linear model constructed from a set of bottom pressures and concurrent tide-staff measurements. The study reveals that the crucial factor, which determines the effectiveness of the model, is incorporation of datasets from that tidal cycle which encompasses the largest span of water column height during spring tide. The model provides chart-datum-referenced sea level record directly from bottom pressure measurements without the use of seawater density measurements. This methodology improves the precision of bottom pressure based sea level measurements, particularly in turbulent and suspended-sediment-laden shallow coastal and estuarine water bodies, where the effective density of water has been reported to have been lower than that obtained from conventional measurements