Raw secondary low frequency (SLF) echo sounding data initially retrieved during Maria S. Merian cruise MSM66 were converted to standard SGY format for further visualization in geophysical software. Conversion was performed using the PS32SGY tool by Hanno Keil, University of Bremen. Navigation was converted to UKOOA format with coordinates in WGS84. SGY and UKOOA fils are named using the starting date and time of the profile (YYYY_MMDD_HHMMSS). Due to the 12-digits-restriction of profile names in the UKOOA format, the first column of the UKOOA file contains a shortened version of the SGY file name (YYMMDDHHMMSS). This publication contains data from the Clyde River Inlet.