The BMGTools, created by IFREMER, are a set of pre-processing tools that help you to create, check and modify bathymetric grids. CreateBMG is a part of the BMGTools. Its purpose is to help you create a hierarchy of grids on a map, resize them and interpolate bathymetry data on them, either from sounding measurements or numerically computed ground models. The present document is the user manual of CreateBMG.