Ship requirements related to radiocommunications are required to ensure ships are fitted with the necessary equipment, and carry out the proper procedures, to effectively transmit and receive safety, distress and search and rescue communications with shore authorities and other ships. Safety communications include navigation safety calls with nearby ships and the reception of maritime safety information, such as navigational notices and weather warnings and broadcasts. Examples of radio equipment are: maritime mobile-satellite systems; digital selective calling radio equipment; emergency position-indicating beacons, search and rescue transponders and survival craft radios.