: This user s manual describes components, assembly, system configuration, data collection procedures, and data processing activities for the second iteration of the Submersed Aquatic Vegetation (SAV) Early Warning System (SAVEWS Jr.). SAVEWS Jr. uses two frequencies (200 and 800 kHz) from a downward aimed echo sounder to determine the bottom depth and presence/absence of SAV. If SAV is present, canopy height and vegetation percent coverage are estimated. Once collected, the digital data (Lowrance proprietary .SL2 files) are displayed, using the SAVEWS Jr. software. Users then select a configuration file that is appropriate to the environment sampled. A general version of this file is provided with the installation software to serve as a starting point for users to develop their own customized files. After initial processing, a display of classified output (bottom depth and canopy top) is superimposed on the colorized echogram and aligned with data plots of canopy height and percent coverage. Beyond quality assurance graphics, the primary output of SAVEWS Jr. is the .SDF file (SAVEWS data file) which is an ASCII, comma-delimited file containing position-referenced classified output. This can be used directly in statistical analyses or mapping software.