In this paper a theoretical and experimental analysis of the time-domain properties of the Power Line Communication (PLC) channel on-board a cruise ship is presented. It is shown that a typical feature of the topology of this kind of naval power networks strongly reduces the time variation of the transfer function for broadband PLC. In particular the topology uses a star configuration, and each electrical node is a switchboard where tens of cables are connected. An experimental analysis carried out on-board a cruise ship shows that when this kind of nodes are present along the path between the PLC transceivers, the time variations of the frequency response due to load switching are significantly reduced. This phenomenon is demonstrated also following a theoretical approach and by numerical experiments.