An officer certified to operate GMDSS equipment and manage all radio communications on board; a role increasingly merged with other duties.
In practice
On certain vessel types — cruise ships, naval auxiliaries, and cable ships — a dedicated radio officer or communications officer may still be employed. Their duties include maintaining all GMDSS equipment in serviceable condition, testing EPIRB registration and battery status, conducting daily radio schedules with the company and coast stations, maintaining the radio log, and operating the ship's internal and external communications networks including satellite systems (Inmarsat, Iridium) and VHF/MF/HF equipment. Under SOLAS IV, certain GMDSS equipment must have battery backup, and the radio officer is responsible for verifying these reserves regularly.
Regulatory detail & full definition
A radio officer is an officer certified to operate GMDSS communications equipment and to manage all radio communications aboard a vessel. The GMDSS framework introduced by the 1988 SOLAS amendments and mandatory from 1999 replaced the traditional Morse-code radio officer role with a system of equipment-based sea area coverage and distributed responsibility. Today, the GMDSS Radio Operator certificate (GOC or ROC, depending on the sea area) is commonly held by deck officers as part of their STCW qualifications under chapter IV, rather than being a separate career.
On certain vessel types — cruise ships, naval auxiliaries, and cable ships — a dedicated radio officer or communications officer may still be employed. Their duties include maintaining all GMDSS equipment in serviceable condition, testing EPIRB registration and battery status, conducting daily radio schedules with the company and coast stations, maintaining the radio log, and operating the ship's internal and external communications networks including satellite systems (Inmarsat, Iridium) and VHF/MF/HF equipment. Under SOLAS IV, certain GMDSS equipment must have battery backup, and the radio officer is responsible for verifying these reserves regularly.