GMDSS Radio Maintainer’s License

The GMDSS Radio Maintainer’s License (DM) qualifies personnel as GMDSS radio maintainers to perform at sea repair and maintenance of GMDSS equipment.

It also confers the operating authority of the General Radio Telephone Operator (PG) and Marine Radio Operator Permit (MP). The GMDSS Maintainer’s License test consists of the exams for FCC Element 1, FCC Element 3, and FCC Element 9.

  • FCC Element 1 — Basic radio law and operating practice with which every maritime radio operator should be familiar. To pass, an examinee must correctly answer at least 18 out of 24 questions.
  • FCC Element 3 — General Radiotelephone. Electronic fundamentals and techniques required to adjust, repair, and maintain radio transmitters and receivers. The exam consists of questions from the following categories: operating procedures, radio wave propagation, radio practice, electrical principles, circuit components, practical circuits, signals and emissions, and antennas and feed lines.

    To pass, an examinee must correctly answer at least 57 out of 76 questions.

  • FCC Element 9 — GMDSS Radio Maintenance Practices and Procedures. Requirements set forth in IMO Assembly on Training for Radio Personnel (GMDSS), Annex 5 and IMO Assembly on Radio Maintenance Guidelines for the Global Maritime Distress and Safety System related to Sea Areas A3 and A4. The exam consists of questions from the following categories: radio system theory, amplifiers, power sources, troubleshooting, digital theory, and GMDSS equipment and regulations.

    To pass, an examinee must correctly answer at least 38 out of 50 questions.

To qualify, you must:
  • Be a legal resident of (or otherwise eligible for employment in) the United States; and
  • Be able to receive and transmit spoken messages in English; and
  • Pass a written and/or telegraphy examination(s) as described above.
A GMDSS Radio Maintainer’s License is issued for the holder's lifetime. (Prior to March 25, 2008, the license term for a GMDSS Radio Maintainer’s License was five years.

Any holder of a GMDSS Radio Maintainer’s License that expired prior to March 25, 2008, must still file an application to renew the license within the five-year grace period after expiration.)