Collaborative virtual environments (CVEs) such as massive multi-user 3D games and military training environments can place strict requirements on network when participating users are sharing the 3D virtual environment through mobile devices in an ad hoc network. This paper describes the proposal and evaluation of a peer-to-peer network over mobile Adhoc networks (MANETs) in order to support largescale CVEs. We show how a CVE application can be efficiently deployed on the Gnutella peer-to-peer network over an Ad-hoc network. The overlay network manages the mobile device resources with a fair workload by using mobile ultrapeers and a node gateway. The overlay also handles tolerance to mobility and routing recovery, which is based on a novel discovery technique, in which mobile nodes are found through both their state and position in the CVE.