GMDSS Course

Lesson 1 • History and Purpose of GMDSS

Traces the evolution from Morse-based distress systems to GMDSS. Provides context for why the system was adopted and what safety gaps it addresses.

Lesson 2 • Operator Roles and Watch-Keeping Duties

Defines the responsibilities of GMDSS operators during normal and emergency operations. Establishes the foundation for all procedural chapters that follow.

Lesson 3 • GMDSS Sea Areas Defined

Defines the four sea areas A1 through A4 and their coverage characteristics. Determines which equipment a vessel must carry based on its operating area.

Lesson 4 • GMDSS Functional Requirements

Identifies the nine communication functions every GMDSS installation must fulfill. Links each function to specific equipment and operational scenarios.

Lesson 1 • VHF Band Characteristics and Uses

Covers VHF frequency range, propagation behavior, and designated maritime channels. Connects VHF capabilities to sea area A1 operations and on-scene communications.

Lesson 2 • Fundamentals of Radio Wave Propagation

Introduces ground wave, sky wave, and space wave propagation modes. Provides the physical basis for understanding why different frequencies behave differently at sea.

Lesson 3 • Satellite Communication Propagation

Explains geostationary and low-earth-orbit satellite signal paths relevant to GMDSS. Establishes the propagation basis for Inmarsat and Cospas-Sarsat systems.

Lesson 4 • HF Band Characteristics and Uses

Describes HF sky wave propagation, frequency selection by time and season, and long-range maritime use. Prepares students for sea area A4 HF radio operations.

Lesson 1 • DSC Controller Integration and Testing

Addresses DSC controller programming, position input, and periodic self-testing. Ensures students can maintain DSC equipment in a state of operational readiness.

Lesson 2 • DSC Distress Alerting Procedures

Covers the step-by-step process for sending and acknowledging DSC distress alerts. Directly supports the primary GMDSS functional requirement for distress alerting.

Lesson 3 • DSC Routine and Individual Calls

Teaches how to initiate and respond to routine ship-to-ship and ship-to-shore DSC calls. Builds practical operating skill for everyday GMDSS communications.

Lesson 4 • DSC System Architecture and MMSI

Explains how DSC encodes identity, call category, and position data digitally. Introduces MMSI structure and registration as the foundation for all DSC operations.

Lesson 1 • Urgency and Safety Voice Procedures

Covers PAN PAN and SECURITE call formats, content requirements, and appropriate situations. Reinforces the priority hierarchy established in the DSC chapter.

Lesson 2 • Distress Communication Sequence

Walks through the full distress procedure from initial DSC alert to voice MAYDAY and rescue coordination. Integrates DSC knowledge from Chapter 3 into a complete emergency workflow.

Lesson 3 • False Alerts and Interference Prevention

Addresses the causes, consequences, and cancellation procedures for inadvertent distress alerts. Develops responsible operating habits that protect the integrity of the distress system.

Lesson 4 • Radio Silence and Frequency Discipline

Teaches when and how to impose or observe radio silence during distress traffic. Reinforces frequency discipline as a critical safety behavior.

Lesson 1 • PLBs and Portable VHF Radios

Addresses personal locator beacons and handheld VHF radios carried in survival craft. Completes the student's knowledge of all portable GMDSS locating and communication devices.

Lesson 2 • EPIRB Installation, Activation, and Testing

Covers float-free bracket installation, hydrostatic release, manual activation, and self-test procedures. Ensures students can deploy and verify EPIRBs correctly in any scenario.

Lesson 3 • EPIRB Types and Cospas-Sarsat System

Explains 406 MHz EPIRB operation and how Cospas-Sarsat satellites detect and process alerts. Establishes the technical basis for understanding EPIRB registration and performance.

Lesson 4 • AIS-SART Capabilities and Limitations

Compares AIS-SART with radar SART and explains how AIS-SART transmits position to AIS displays. Helps students select and use the appropriate locating device.

Lesson 1 • Fleet Broadband and Higher-Bandwidth Terminals

Introduces Fleet Broadband and similar high-speed satellite terminals used for voice, data, and distress. Expands student knowledge beyond legacy Inmarsat-C to modern shipboard systems.

Lesson 2 • Iridium and Non-Geostationary Systems

Explains LEO satellite systems such as Iridium and their role in polar and global coverage. Addresses sea area A4 communication options where geostationary coverage is unavailable.

Lesson 3 • Satellite Terminal Maintenance and Faults

Addresses routine maintenance, log-on failures, antenna alignment, and fault diagnosis for satellite terminals. Prepares students to keep satellite equipment operational at sea.

Lesson 4 • Inmarsat System Architecture

Describes the Inmarsat geostationary satellite network, land earth stations, and vessel terminals. Provides the system-level understanding needed to operate and troubleshoot satellite equipment.

Lesson 1 • MSI Sources and Responsibilities

Identifies the types of MSI and the international bodies responsible for their broadcast. Establishes the regulatory and operational context for all MSI reception equipment.

Lesson 2 • SafetyNET via Inmarsat-C EGC

Explains how SafetyNET delivers MSI via Inmarsat-C EGC to vessels in sea areas A3 and A4. Builds on Inmarsat-C knowledge from Chapter 6 to complete MSI reception coverage.

Lesson 3 • NAVTEX System Operation

Covers 518 kHz and 490 kHz NAVTEX receiver setup, station and message type selection, and message interpretation. Connects NAVTEX reception to the MSI functional requirement.

Lesson 4 • Integrating MSI into Voyage Planning

Teaches how to apply received MSI to route decisions, chart corrections, and safety briefings. Bridges the gap between MSI reception and practical navigational decision-making.

Lesson 1 • Equipment Testing and Inspection Schedules

Details daily, weekly, and monthly testing requirements for all GMDSS equipment. Builds systematic maintenance habits that satisfy port state control inspections.

Lesson 2 • Fault Diagnosis and Corrective Action

Develops a systematic approach to identifying and resolving common GMDSS equipment faults. Prepares students to restore communications quickly during critical situations at sea.

Lesson 3 • Antenna Systems and Connections

Addresses VHF, MF/HF, and satellite antenna installation, inspection, and fault finding. Antenna integrity is critical to the range and reliability of all GMDSS transmissions.

Lesson 4 • GMDSS Maintenance Methods

Explains the three approved maintenance methods: shore-based, duplication, and at-sea maintenance. Establishes the regulatory framework for all equipment maintenance decisions.