In 1995, NOAA began developing the Deep-ocean Assessment and Detection of Tsunami (DART) system to provide better warnings for tsunami-prone communities. Until 2004, the U.S. operated 6 systems in the Pacific Ocean, but the network expanded to 39 buoys operating in the Pacific and Atlantic Oceans, the Caribbean, and the Gulf of Mexico. The tsunami buoy and its companion sea-floor sensor use satellite communication to transmit tsunami wave information to Tsunami Warning Centers around the globe.