Make two parallel passes of the area to be surveyed separately
Open the SL2 file with RM and edit as need.
Export it with RM as ESRI GRID.
Open ESRI GRID with Global mapper
Create point features at elevation grid, assign points to it as spot sounding
Export as CSV
Open the CSV with excel and edit the ELEVATION column by removing decimals to need
Open the CSV already corrected with RM or GM or any other soft.
Here you can see a 3D made with GM
Multibeam Soundings
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