GMDSS Equipment Tests: Daily, Weekly and Monthly

GMDSS GUIDE · EQUIPMENT CHECKS

Ready for the next watch

Daily, weekly and monthly checks of radio equipment, reserve power and emergency locating devices.

Sources checked: 8 November 2026

Choose the schedule that applies to your ship
This learning guide adapts the supplied checklist. Confirm every interval against the flag Administration’s requirements, the vessel’s safety management system (SMS) and the equipment manual. The MCA schedule cited below is a UK example, not a universal rule for every flag. [3, 5]

01 · Internal tests and readiness

Daily checks

VHF DSC and MF/HF DSC

Run the built-in DSC self-test without radiating a signal. Check the result and any fault indications.

VHF radiotelephone

Check the operating display, power indicators and required watchkeeping settings, including Channel 16 where applicable.

Radio batteries and charger

Check charge condition, voltage indications and charger status. If the approved procedure calls for on-load and off-load readings, follow the equipment instructions; do not improvise a transmission or a discharge test.

Printers and displays

Check for faults and, where printers are fitted, sufficient paper. [3]

02 · Controlled operational tests

Weekly checks

DSC test call

Where required, make the prescribed test call to a suitable coast station within range. If out of range, record this and test at the first appropriate opportunity. For MF/HF, follow COMSAR/Circ.35 and the station’s procedures. [3, 4]

VHF DSC

Do not assume every VHF set or coast station supports a dedicated DSC test call. Use the approved method for the installed equipment; do not substitute a distress alert.

Other reserve energy sources

Include a non-battery reserve source, if fitted, in the applicable weekly programme. [3]

03 · Condition, expiry dates and self-tests

Monthly checks

EPIRB

Use the built-in self-test as permitted by the manual. Inspect the casing and mounting, and check the battery and hydrostatic release unit (HRU) expiry dates. A GNSS self-test may have its own limits.

Radar SART and AIS-SART

Use the designated test mode and the manufacturer’s procedure. Check the response on the appropriate X-band radar or AIS display as applicable to the device; inspect the casing and battery expiry date.

Survival-craft portable VHF radios

Use the designated test or rechargeable battery and an authorised working channel other than Channel 16. Keep sealed emergency batteries intact and check their expiry dates.

Reserve batteries

Inspect security, connections and general condition. Check electrolyte level and specific gravity only where appropriate for that battery type and required by the manual; do not open sealed batteries.

Antennas, insulators and cables

Inspect for visible damage, corrosion and loose connections using safe access arrangements. [3]

NAVTEX and satellite terminals

Check reception of maritime safety information (MSI), relevant settings, terminal login or network status, and fault indications under the onboard procedure. Schedule NAVTEX diagnostics, EGC reception checks and satellite link/PV tests according to the installed system’s manual and SMS. Do not treat an Inmarsat-C PV test as a universal weekly requirement or apply its procedure unchanged to Iridium.

A capacity test is a separate task

A routine voltage or condition check does not establish battery capacity. COMSAR.1/Circ.32/Rev.3 §7.4.6 recommends checking radio battery capacity at intervals not exceeding 12 months, when the ship is not at sea. Use the approved method and avoid significant battery discharge at sea. [2]

Record the result in the radio log

Enter the UTC date and time, equipment identification, test method, actual result and operator. For a test call, include the station contacted and acknowledgement; record faults, action taken and notification to the Master. Follow the flag’s rules for review and signatures. [5]

UTC date / time	Equipment / test	Actual result / action	Operator
[date and UTC]	[set ID and test mode]	[observed result; faults and follow-up]	[name / signature]

Example fields only. Fill in actual observations after the check; this web page is not the vessel’s radio log.

What the regulations cover

SOLAS IV/13 addresses sources of energy; IV/15 addresses maintenance and equipment availability; IV/17 requires radio records important to safety. The detailed onboard test programme also depends on flag requirements and equipment instructions. COMSAR.1/Circ.32/Rev.3 gives installation and power guidance, not a universal daily/weekly/monthly test schedule. [1, 2]

Sources and applicability

The links below distinguish the SOLAS framework, IMO guidance and examples from individual Administrations. For an actual ship, use the current requirements applicable to its flag and equipment.