Grauch and Campbell have raised an important question about the uses of draped flying. However, certain common geologic situations which draped flying is intended to address are not discussed in their paper. One example is the case in which shallow, high-susceptibility material overlies magnetic structures of interest at considerable depth. The shallow material may be a relatively thin, surficial or near-surficial volcanic flow. An appropriate model for this situation would be a uniformly magnetized dipole sheet located at the surface of the topography, with prismatic bodies buried at depth.