  Energy positivity is established for a class of solutions to Einstein-aether
theory and the IR limit of Ho\v{r}ava gravity within a certain range of
coupling parameters. The class consists of solutions where the aether 4-vector
is divergence free on a spacelike surface to which it is orthogonal (which
implies that the surface is maximal). In particular, this result holds for
spherically symmetric solutions at a moment of time symmetry.
