  Smectic-C elastomers can be prepared by crosslinking, e.g., liquid crystal
polymers, in the smectic-A phase followed by a cooling through the smectic-A to
smectic-C phase transition. This transition from $D_{\infty h}$ to $C_{2h}$
symmetry spontaneously breaks rotational symmetry in the smectic plane as does
the transition from a smectic-A to a biaxial smectic phase with $D_{2h}$
symmetry. We study these transitions and the emergent elasticity of the
smectic-C and biaxial phases in three related models and show that these phases
exhibit soft elasticity analogous to that of nematic elastomers.
