A software called BathyMeshGridTools is proposed to facilitate the construction of gridded bathymetry data for hydrodynamic ocean models from global to coastal scales. These tools consist of a graphical interface written in Java and a computational core written in FORTRAN, which are freely distributed under LGPL and GPL licenses (http://www.ifremer.fr/bmgtools). The process of gridded bathymetry creation relies on three successive tasks : (1) creation of structured grid using graphic user interface for positioning, resizing and creating a hierarchy of nested model grids on map ; (2) data interpolation using a grid-to-grid interpolation algorithm for interpolation of Digital Terrain Model and kriging algorithm for bathymetric sounding data interpolation ; (3) visual inspection and manual editing of the interpolated bathymetry field. These three steps can be used in the same process of construction of bathymetry gridded data and can also be used independently (e.g. one can use only the visualization tool for checking and modifying manually a bathymetry field previously created with an other tool).