Maritime at sea networks are particularly difficult to manage due to their dynamic and heterogeneous low-bandwidth links. The policy-based network management (PBNM) approach offers techniques to automate network management. It allows operators to dynamically change the behaviour of managed systems in response to evolving operational needs without requiring per device intervention. A research effort was initiated to investigate the effective management of communication resources in a tactical maritime environment using a combination of Web Services (WS) and policy-based techniques. A management architecture was developed and an experimental prototype was implemented. This paper presents the implementation of the Policy-Based Traffic Management (PBTM) prototype and its demonstration in a laboratory using a simulated naval task deployment testbed. Observations on the performance of the policy system are provided.