Within this paper we present a cooperative adaptive algorithm for the management of a team of Autonomous Underwater Vehicles (AUVs) that are the mobile nodes of an ad-hoc underwater network and share the mission objective of protecting an asset while maintaining reliable acoustic communication links among themselves. Each vehicle is considered to be equipped with a detection sonar for asset protection and with an acoustic modem for communication purposes. The performance of the algorithm is shown with respect to optimal geometric solutions, and through the simulation of the underneath acoustic network to verify the performance in scenarios characterized by long propagation delays, high packet losses and unreliable communication links.