The Countermine System (CMS), also known as Venom Darts, Venom Penetrators and GBU-61, is an anti-land-mine system consisting of chemical or explosive projectiles released from modified GPS-guided bombs. The darts are used to detonate or deactivate land mines in beach and surf zones. The system was developed by the United States (U.S.) Navy and Boeing at an initial cost of US$153-million. The CMS is expected to be field ready by 2016.