Electrostatic potential grids can be computed through the numerical solution of the Poisson-Boltzmann equation using for example the APBS package. DX-formatted electrostatic potential files can then be used as inputs for Surface Diver. We suggest to use the van der Waals definition of the molecular surface during computations of electrostatic potentials. However, if one uses a non-zero irad parameter, different definitions are also possible (for example the solvent accessible surface).