UHF is good for caravans because it's somewhat more immune to interference, because... Anyone? Anyone?
What are a couple of the propagation properties that make UHF nice for simplex talk groups? It's not a mistake that FRS radios were put on UHF, for example.
Also, UHF can be interesting because of what environmental phenomenon? Anyone? It happens over large geographical features, like oceans and near mountains often.
"Silent enim leges inter arma." -- Cicero