The perturbations produced in the proton transfer potential of (H2OHOH2)+ by a number of ions and dipoles in various locations around the system are calculated with the 4-31G basis set. The observed perturbations are fully consistent with an electrostatic picture in which the positively charged proton is pushed along the lines of force emanating from the external object. As was observed previously for ions, the effects of the dipoles are magnified by the H bond, relative to their Coulombic interaction with a bare proton. The perturbations produced in the transfer potential by an array of multiple charges or dipoles are found to be almost completely additive.