raster - QGIS and BSB files for 3D Printing

I am new to GIS. I'm a sailor and 3D printing enthusiast.

What I want is to print a 3D representation of my sailing area.

I've acquired the raster files for my navigation charts and they consists of .kap and .bsb which is what is required for QGIS.

I have the raster files in KAP and BSB format. However when I open the KAP files in QGIS I see only 6 or 7 layers. When I open a NOAA file in the same format, I see there are over 30 layers.

I also installed the DEMto3D plugin to generate the STL files to send to the printer.

I'm not sure that the data set contains enough details to allow me to do what I what. I end up getting a file with no depth.

Running QGIS 2.18.23 on Mac