The first example (UWSim) is a very specific DVL message for an RDI DVL while the second (uuv_simulator) for me is more generic. The only problem that I see with the second is that most of DVL sensors can provide measurements wrt. sea bottom or/and wrt. water. However, changing the velocity_covariance or publishing two topics (one for bottom and another for water measurements) will be enough.
We could start the discussion using the (uuv_simulator) as a base. For the Side Scan Sonar, and example can be found at SSS msg.