An abstract characterization of the networked vehicle systems under study is presented together with the corresponding modeling, coordination and control challenges. This is done with the help of an example of 24/7 persistent operations. The novel aspects of these systems are emphasized and the nature of the new challenges is discussed. This is done with reference to fundamental concepts in control and computation, namely state and control spaces, control strategies, optimization, behavior equivalence, process, interaction and composition. The discussion is illustrated with tools and technologies from the Underwater Systems and Technologies Laboratory from Porto University.