Choose your language
GMDSS Restricted Operator Certificate (ROC) Course
More than 2 million students worldwide

GMDSS Restricted Operator Certificate (ROC) Course

The GMDSS Restricted Operator Certificate course gives you the technical knowledge and hands-on procedures required to operate maritime distress and safety communication systems with confidence. You will master DSC alerting, VHF voice procedures, EPIRB and SART operation, satellite communications, and NAVTEX reception. This course prepares you fully for the ROC written examination and practical assessment.

Dedika for Business

What you will learn:

You will learn the GMDSS framework as defined by SOLAS and ITU and your legal duties as a certified radio operator. The course covers Digital Selective Calling on VHF, MF, and HF for distress, urgency, safety, and routine calls. You will acquire hands‑on skills operating EPIRBs, SARTs, AIS‑SARTs, and Inmarsat‑C satellite terminals. NAVTEX receiver setup and SafetyNET message reception are taught for voyage planning. Search‑and‑rescue scenarios train you to manage on‑scene coordination. Equipment maintenance, power‑supply management, and cybersecurity awareness complete your preparation. By course end you will be ready to pass the ROC assessment and perform all GMDSS communication functions aboard a vessel.

How you study in practice GMDSS Restricted Operator Certificate (ROC) Course

How you practise GMDSS Restricted Operator Certificate (ROC) Course

For companies looking to train their team

With Dedika for Business, the course includes exercises and examples tailored to your own business and the way your company needs.

Click here

Course Content

8 Chapters • 39 LessonsDuration between 4 and 360 hours (you decide)

Chapter 1See details

GMDSS Framework and Regulatory Foundations

  • Lesson 1 • Operator Roles and Responsibilities

    Defines the duties of a GMDSS radio operator aboard a vessel. Establishes accountability for watch-keeping, maintenance, and log-keeping.

  • Lesson 2 • GMDSS Sea Areas Defined

    Defines the four sea areas A1 through A4 and their coverage characteristics. Determines which equipment is mandatory for each area.

  • Lesson 3 • Origins and Purpose of GMDSS

    Traces the evolution from Morse-based distress systems to GMDSS. Provides context for why the system exists and what problems it solves.

  • Lesson 4 • International Regulatory Structure

    Identifies the international bodies governing GMDSS and their roles. Links regulatory authority to operator certification requirements.

  • Lesson 5 • Functional Requirements of GMDSS

    Outlines the nine communication functions every GMDSS-equipped vessel must fulfill. Connects each function to specific equipment and procedures.

Chapter 2See details

Radio Wave Propagation and Frequency Bands

  • Lesson 1 • Frequency Bands Used in GMDSS

    Surveys VHF, MF, HF, and satellite frequency allocations relevant to GMDSS. Links each band to its propagation characteristics and sea area coverage.

  • Lesson 2 • Interference and Noise Sources

    Identifies natural and man-made sources of interference affecting GMDSS communications. Prepares operators to recognize and mitigate signal degradation.

  • Lesson 3 • Antenna Systems and Polarization

    Describes antenna types used in maritime radio and their radiation patterns. Connects antenna selection to effective communication range and reliability.

  • Lesson 4 • Fundamentals of Radio Wave Propagation

    Explains how electromagnetic waves travel through and around the Earth. Establishes the physical principles underlying all GMDSS frequency choices.

Chapter 3See details

Digital Selective Calling Operations

  • Lesson 1 • DSC Urgency and Safety Calls

    Distinguishes urgency and safety call procedures from distress and explains when each is appropriate. Builds correct decision-making for non-distress priority calls.

  • Lesson 2 • DSC Distress Alerting Procedures

    Trains operators to initiate and respond to DSC distress alerts on Channel 70 and MF/HF distress frequencies. Covers both automated and manual alert composition.

  • Lesson 3 • MMSI Registration and Configuration

    Covers how MMSIs are assigned and programmed into DSC controllers. Ensures operators can verify and update vessel identity data correctly.

  • Lesson 4 • DSC Routine and Individual Calls

    Covers ship-to-ship and ship-to-coast routine DSC calling procedures. Develops proficiency in everyday DSC use beyond emergency scenarios.

  • Lesson 5 • DSC Principles and Message Structure

    Explains how DSC encodes identity, priority, and message content in a digital burst. Establishes the logic behind call categories and format fields.

Chapter 4See details

VHF Radiotelephone Procedures

  • Lesson 1 • Phonetic Alphabet and Prosigns

    Drills the ITU phonetic alphabet and standard procedural words used in voice radio. Ensures clear, unambiguous transmission in all conditions.

  • Lesson 2 • VHF Channel Assignments and Watch

    Maps VHF channels to their designated purposes in the maritime mobile service. Establishes mandatory watch requirements on Channel 16 and Channel 70.

  • Lesson 3 • Urgency and Safety Voice Procedures

    Covers PAN PAN and SECURITE call formats and their appropriate use. Distinguishes these from distress and routine traffic in decision-making.

  • Lesson 4 • Distress Voice Procedures

    Trains the full MAYDAY call sequence and subsequent distress traffic management. Covers both initiating and receiving vessel roles.

  • Lesson 5 • Routine VHF Communication Practice

    Develops fluency in everyday ship-to-ship and ship-to-port communications. Reinforces correct call setup, message passing, and sign-off procedures.

Chapter 5See details

EPIRB, SART, and Survival Craft Equipment

  • Lesson 1 • EPIRB Types, Registration, and Testing

    Distinguishes float-free and manual EPIRBs and their installation requirements. Covers registration, battery replacement, and self-test procedures.

  • Lesson 2 • Radar Transponders: SART Operation

    Explains how 9 GHz SARTs respond to X-band radar sweeps to create a locating pattern. Trains correct activation and positioning for maximum detection.

  • Lesson 3 • Survival Craft Radio Equipment

    Identifies portable VHF radios and other communication devices required in survival craft. Trains correct use during abandonment and rescue phases.

  • Lesson 4 • EPIRB Technology and Cospas-Sarsat System

    Explains how EPIRBs transmit distress signals and how the Cospas-Sarsat satellite network processes them. Links signal encoding to SAR response speed.

  • Lesson 5 • AIS-SART and PLB Devices

    Covers AIS-SART operation as an alternative to radar SART and introduces personal locator beacons. Compares detection methods and operational advantages.

Chapter 6See details

Satellite Communication Systems

  • Lesson 1 • Inmarsat-C Terminal Operations

    Trains operators to send and receive messages, distress alerts, and EGC broadcasts via Inmarsat-C. Covers terminal setup, polling, and position reporting.

  • Lesson 2 • Inmarsat Voice and Data Services

    Covers Fleet Broadband and legacy voice services for ship-to-shore communication. Distinguishes service tiers and their applicability to GMDSS requirements.

  • Lesson 3 • Satellite Distress Alert Procedures

    Consolidates distress alerting via all satellite paths available in GMDSS. Trains operators to select the appropriate satellite system under emergency conditions.

  • Lesson 4 • Iridium and Non-Geostationary Systems

    Introduces low-Earth-orbit satellite systems as complements or alternatives to Inmarsat. Addresses polar coverage advantages relevant to high-latitude voyages.

  • Lesson 5 • Inmarsat System Architecture

    Describes the Inmarsat geostationary satellite network and its ocean region coverage. Establishes the infrastructure underlying Inmarsat-C and Fleet services.

Chapter 7See details

Maritime Safety Information and NAVTEX

  • Lesson 1 • MSI Categories and Sources

    Defines the types of maritime safety information and the authorities that issue them. Establishes why continuous MSI reception is a GMDSS functional requirement.

  • Lesson 2 • NAVTEX Receiver Configuration and Use

    Trains practical setup and operation of a NAVTEX receiver for a planned voyage. Covers station selection, message storage, and printer management.

  • Lesson 3 • SafetyNET and Inmarsat-C MSI

    Covers satellite-delivered MSI via SafetyNET for sea areas beyond NAVTEX coverage. Trains operators to configure Inmarsat-C terminals for EGC reception.

  • Lesson 4 • Acting on MSI in Voyage Planning

    Applies received MSI to practical navigation decisions and watch-keeping. Bridges the gap between information reception and operational response.

  • Lesson 5 • NAVTEX System Architecture

    Explains the NAVTEX broadcast network, station identifiers, and subject indicators. Enables operators to configure receivers for relevant geographic areas.

Chapter 8See details

Search and Rescue Communications

  • Lesson 1 • On-Scene Communication Procedures

    Trains communication between vessels and aircraft during an active SAR operation. Covers frequency selection, message formats, and information exchange.

  • Lesson 2 • Integrated Distress Scenario Practice

    Applies all GMDSS systems in a simulated multi-vessel distress scenario. Develops decision-making, system selection, and communication management under pressure.

  • Lesson 3 • SAR Organization and Coordination

    Explains the structure of maritime SAR systems and the roles of RCCs and OSCs. Provides the organizational context for all on-scene communications.

  • Lesson 4 • Locating Signals and Homing

    Covers the use of SART, AIS-SART, and portable VHF for locating survivors. Trains operators to home on signals and guide rescue assets.

  • Lesson 5 • False Alert Management

    Addresses the serious problem of false distress alerts and operator responsibilities. Trains correct cancellation procedures and reporting obligations.

Certification

Your valid completion certificate

This course is for you:

  • Deck cadet: needs ROC certification to meet officer of the watch requirements.

  • Recreational offshore sailor: wants legal authority to operate GMDSS equipment independently.

  • Fishing vessel skipper: must hold a valid operator certificate for regulated waters.

  • Career changer entering maritime: needs a recognized credential to enter the industry.

  • Superyacht crew member: requires formal radio certification for blue-water passage compliance.

  • Coast guard auxiliary volunteer: seeks structured training to handle distress communications correctly.

What our students say

Your classes are perfect. I purchased the one-year package and finally have the opportunity to follow various topics of interest without needing to switch platforms... I thank you for everything you do, I've already recommended you to other people...
Giulio Carlo
Giulio CarloDigital Marketing Student
I like how the lessons are straight to the point and how I can change chapters and skip content I don't need.
Mariana Ferres
Mariana FerresPhotography Student
I like the content and the presentation style and video transcription, which speeds up the process!
Luciana Alvarenga
Luciana AlvarengaNail Design Student
The platform is fast, simple to use. The diversity of content and complementary videos really help with learning.
André Felipe
André FelipePrompt Engineering Student

Top training programs

FAQ

Who is Dedika?

Is the certificate valid in Canada?

Are the courses free?

What is the course workload?

What are the courses like?

How do the courses work?

What is the duration of the courses?

What is the cost or price of the courses?

What is an EAD or online course and how does it work?

PDF Course