  We study the propagation of dispersive waves in superfluid Fermi gases in the
BEC-BCS crossover. Unlike in other superfluid systems, where dispersive waves
have already been studied and observed, Fermi gases can exhibit a subsonic
dispersion relation for which the dispersive wave pattern appears at the tail
of the wave front. We show that this property can be used to distinguish
between a subsonic and a supersonic dispersion relation at unitarity.
