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.

Term of License

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.)

How to Take the Exam

There are two ways to take the exam:

  1. Online Exam. This method allows you to take the exam from any location that has internet access using our remote proctored exam process. To take the exam, you must complete the online registration form found at the end of this page and pay your fee. Once you are registered and your payment has been received, you will be sent a link to the exam. You may take the exam at home, at work, or anywhere you have an undisturbed space that our remote proctor can observe via your webcam. Please see our online exam requirements here.
  2. Test Center-Administered Exam. This method allows you to take the exam with a live proctor at any of our 190 global test centers. You will need to select a test center during the registration process. After you have registered, you will receive information on how to schedule your exam date and time. Please note that if you select this exam method, you are responsible for paying the proctor fee directly to the test center. This fee is not included in the exam fee collected by iNARTE Exemplar Global. Please see our test-center-administered exam requirements here.

Regardless of the method selected, your test results will be available to you immediately following the conclusion of the exam.

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