Operation fields often give rise to situations where com- munication has to be carried out without any infrastructure. One of the solutions that can be used to support this context is based on mobile ad hoc networks (MANets). We believe that when this kind of versatile architecture is considered it is necessary to have dedicated services that take their con- text into account and still work in case the network is slow or even broken, instead of relying on a routing layer. Sit- uation management and more precisely battlefield situation management can thus still be supported in spite of poor com- munication conditions. The application that we present in this paper illustrates this approach. It makes it possible to share a map of the bat- tlefield between soldiers. Its major originalities are that it is totally decentralized and that it handles what we call active information. Active information are information that are up- dated by the different entities of the network. Applications that use active information have never been experimented in a military context. Two major difficulties when designing such applications are to clearly define their context of use and the associated limitations, and to provide a significant evaluation. We ad- dress these problems in this paper, based on our prototype implementation. The work presented in this paper is carried out at LaBRI (Laboratoire Bordelais de Recherche en Informatique) and more precisely in the SOD (Syst`emes et Objets Distribu´es) research team. It is partly achieved within the framework of the Sarah (Services Asynchrones pour R´eseaux Ad Hoc) project supported by the ANR. It is also partly supported by the DGA by means of a PhD grant.