A measure of quality for both raw and smoothed 3-D data collected at NUWES (Naval Undersea Warfare Engineering Station) is proposed and illustrated in this report. This measure, called a Figure-of-Merit, is based on polynomial fitting by the Least-Squares method to data segments. It is derived by establishing confidence intervals for the differences between observed and smoothed (estimated) values of vehicle coordinates at the observation times. The proposed Figure-of-Merit provides numerical bounds (statistical bounds) for this difference.