406 MHz EPIRB
medium
6 models total
A 406 MHz EPIRB transmits a coded distress message via the COSPAS-SARSAT satellite system and, when fitted with an internal GPS receiver, encodes the ship's position to within about 100 metres, unlike a SART, which stays silent until a rescuer is already close by.
Read more — 406 MHz EPIRB explained ▾
What sets a 406 MHz EPIRB apart from a SART
A 406 MHz EPIRB is an alerting device: once activated it transmits a digitally coded distress message to the COSPAS-SARSAT satellite constellation, giving rescue coordination centres the vessel's identity and, on GPS-equipped units, its position within roughly 100 metres inside a few minutes. A SART does the opposite job. It stays silent until interrogated by a searching vessel's 9 GHz radar, then paints a line of dots on that radar screen to guide the final approach. An EPIRB tells the world a ship is in distress; a SART only helps a rescuer already in the area find the survivors.
Main components
406 MHz transmitter and unique identifier
Each beacon is programmed with a unique 15-character hexadecimal identifier tied to the ship's MMSI or IMO number in a national beacon register. This identifier, not the position alone, is what lets a rescue centre pull up the vessel name, owner contact and crew number within seconds of the first satellite pass.
Internal GPS receiver
Modern beacons carry their own GPS module rather than relying only on Doppler positioning from the satellite pass. GPS-encoded position cuts the time to an accurate fix from roughly an hour, under the older Doppler-only method, down to a few minutes.
121.5 MHz homing beacon
A separate low-power transmission used by search aircraft and ships for final homing once the satellite system has already narrowed the search area; it is not itself monitored by satellite anymore.
Hydrostatic release unit (HRU)
A weak-link and water-soluble pin assembly that releases the float-free bracket at roughly 1.5 to 4 metres depth if the ship sinks before anyone can launch the beacon by hand.
Selection considerations
| Parameter | Typical figure |
|---|---|
| Battery service life (standby) | Replace per manufacturer date, commonly every 5 years |
| Minimum transmission duration once activated | 48 hours continuous |
| Position accuracy, GPS-encoded | ~100 m |
| Position accuracy, Doppler only | 2-5 km, slower first fix |
Regulations and class
SOLAS Chapter IV requires a float-free satellite EPIRB on all GMDSS-fitted ships. The beacon must carry COSPAS-SARSAT type approval and be coded and registered with the flag state or an approved national register before it goes to sea; an unregistered or incorrectly coded beacon delays rescue coordination even though the alert itself still arrives. Class surveys check the expiry date on the battery and HRU, and confirm the coding matches the ship's current name if it has been renamed or reflagged.
Typical faults
| Fault | Consequence |
|---|---|
| HRU past its expiry date | Beacon may fail to release from its bracket if the ship sinks |
| Coding not updated after a change of ship name or flag | Rescue centre pulls up the wrong vessel record, wasting critical minutes |
| Beacon accidentally activated in port | False alert to the rescue coordination centre, must be cancelled immediately through the flag state's MRCC contact |
| GPS antenna obstructed by the bracket mounting | Beacon still alerts but falls back to slower Doppler positioning |
What to look for in a supplier
- Current COSPAS-SARSAT type approval certificate for the specific model, not just the beacon family
- Battery and HRU replacement dates clearly marked and matched to the ship's next scheduled survey
- Support for coding changes through the flag state's register without shipping the unit back to the factory
- Bracket compatible with the ship's existing float-free mounting to avoid re-certifying a new installation
A beacon that has never been registered, or whose registration still shows the ship's previous name, will transmit a perfectly good distress signal that sends the rescue centre looking for the wrong ship first.
5 manufacturers · 6 models
ACR Electronics
2
GlobalFix V4
N/A
· Distress Signal (Satellite/Radar)
· combined EPIRB/SART
Frequency mhz
406
Gps
ja
Battery life hrs
48
Gmdss
ja
Common Failures & Inspection Points
- Battery expiry
- HRU failure
- GPS antenna damage
- Strobe light failure
Service: 6-year battery life. HRU every 2 years. Self-test monthly.
Spare Parts: Ersatzteile über ACR Electronics oder zugelassene Vertriebspartner. Lead time: 2-6 Wochen.
Strengths
- Integrated EPIRB and SART functions reduce equipment count and installation space
- Built‑in GPS provides accurate position data to Cospas‑Sarsat satellites
- Six‑year sealed lithium battery life minimizes replacement frequency
- Automatic water‑immersion activation plus monthly self‑test ensures readiness
- USCG and IMO type approvals guarantee compliance with GMDSS regulations
Weaknesses
- Battery must be replaced after six years, incurring a service cost
- HRU (Hydrostatic Release Unit) requires mandatory inspection/replacement every two years
- Strobe light can fail and is not field‑replaceable, affecting visual detection
- GPS antenna is exposed and may be damaged in harsh marine environments
- Beacon transmission limited to 48 hours; some competitors offer longer duty cycles
Typical Vessels:
TankerContainer shipBulk carrierOffshore supply vesselFishing vesselYacht / large pleasure craft
Certifications:
IMO Performance Standard 406 MHz EPIRBUSCG Type Approval
Decision Guide: Choose if: you need a single, space‑saving unit that provides both satellite distress alert and radar‑visible SART with GPS accuracy, and you operate vessels subject to IMO/USCG GMDSS requirements. Avoid if: you prefer longer beacon duty cycles, want a fully replaceable strobe, or wish to minimize scheduled HRU maintenance.
Use Cases: The GlobalFix V4 is typically installed on the bridge or in dedicated life‑saving stations of ocean‑going merchant ships, offshore platforms, and large yachts. It is also fitted on lifeboats and rescue craft where a combined EPIRB/SART offers rapid location both by satellite and radar during man‑overboard or vessel‑sinking incidents.
RLB-41
N/A
· Distress Signal (Satellite/Radar)
· 406 MHz EPIRB with integrated GPS and SART
Frequency mhz
406
Gps
ja
Gmdss
ja
Common Failures & Inspection Points
- Battery degradation
- HRU failure
- Antenna breakage
Service: Budget EPIRB option. Same battery/HRU service intervals.
Spare Parts: Ersatzteile über ACR Electronics oder zugelassene Vertriebspartner. Lead time: 2-6 Wochen.
Strengths
- Budget‑friendly price compared with premium EPIRBs
- Integrated GPS gives accurate location without external antenna
- Dual function (EPIRB + SART) reduces equipment count and installation space
- Meets GMDSS requirements for most commercial vessels
- Standard battery/HRU service interval simplifies maintenance
Weaknesses
- Reported higher incidence of battery degradation over long storage periods
- HRU (hydraulic release unit) failures have been noted in field reports
- Antenna assembly is considered less robust than on higher‑end models
- Limited advanced diagnostics compared with newer digital EPIRBs
Typical Vessels:
Coastal cargo vesselsFishing boatsOffshore supply & support vesselsPleasure yachts (up to 24 m)Small container or bulk carriers
Certifications:
IMO Type Approval (2006)USCG Approved
Decision Guide: Choose if: you need a cost‑effective, space‑saving EPIRB/SART combo for vessels with moderate risk exposure and can accept the standard service intervals. Avoid if: the vessel operates in high‑risk offshore environments where maximum reliability, redundant power sources, or the latest diagnostic features are required.
Use Cases: The RLB-41 is typically installed on small to medium commercial ships and workboats that require both a distress beacon and a radar transponder but have limited budget for separate units. It is also popular on larger yachts where regulatory compliance with GMDSS is needed without adding extra equipment weight.
Kannad
1
SafeLink EPIRB
N/A
· Distress Signal (Satellite/Radar)
· GPS-enabled 406 MHz EPIRB
Frequency mhz
406
Gps
ja
Gmdss
ja
Origin
France
Common Failures & Inspection Points
- Battery degradation
- HRU failure
- Antenna damage
- GPS fix slow in high latitudes
Service: Orolia group product. 10-year battery option available.
Spare Parts: Ersatzteile über Kannad oder zugelassene Vertriebspartner. Lead time: 2-6 Wochen.
Strengths
- Integrated GPS provides accurate position without manual input
- 10‑year battery option reduces replacement frequency
- Full GMDSS compliance with automatic activation on water ingress
- Robust housing meets harsh marine environment standards
- Orolia network integration enables rapid alert processing
Weaknesses
- Battery performance can degrade if not regularly inspected
- HRU (hydrostatic release unit) failures reported in field service bulletins
- Antenna is exposed and may be damaged by impact or corrosion
- GPS fix may be slower at high latitudes where satellite geometry is poor
- Higher upfront cost compared with basic non‑GPS EPIRBs
Typical Vessels:
Bulk CarrierContainer ShipTankerGeneral Cargo VesselOffshore Support VesselFishing Vessel
Certifications:
IMO Model A (Performance Standard D)USCG Type ApprovalIEC 61097-2
Decision Guide: Choose if you need automatic, high‑accuracy GPS positioning, a long‑life battery option and full GMDSS compliance for merchant or offshore vessels. Avoid if budget constraints favor a basic EPIRB without GPS or if the vessel operates primarily in extreme high‑latitude regions where GPS acquisition time is critical.
Use Cases: Deployed on board merchant ships, offshore platforms, lifeboats and survival craft to provide immediate distress alerts with precise coordinates, enabling rapid SAR response via satellite and coastal rescue coordination centers.
McMurdo
1
SmartFind G8
N/A
· Distress Signal (Satellite/Radar)
· dual‑mode EPIRB with AIS and SART
Frequency mhz
406
Gps
ja
Ais
ja
Battery life hrs
48
Gmdss
ja
Common Failures & Inspection Points
- Battery expiry
- AIS transmitter failure
- HRU degradation
- Water ingress at seal
Service: Dual alert: 406 MHz + AIS. Battery 5-year replacement.
Spare Parts: Ersatzteile über McMurdo oder zugelassene Vertriebspartner. Lead time: 2-6 Wochen.
Strengths
- Dual alert capability – transmits both 406 MHz COSPAS‑SARSAT signal and AIS position for faster detection
- Built‑in GPS delivers precise location without external antenna
- Integrated SART allows automatic radar activation for nearby vessels
- 48‑hour battery endurance after activation and a 5‑year replacement interval
- USCG/IMO approved, ready for SOLAS‑compliant installations
Weaknesses
- Battery must be replaced every five years; expiry can render the unit inoperative
- Reported occasional AIS transmitter failures requiring firmware updates or part replacement
- HRU (human readable unit) degradation over time may affect manual identification
- Potential water ingress at seal if maintenance is neglected
- Higher upfront cost compared with basic 406 MHz‑only EPIRBs
Typical Vessels:
TankersContainer shipsBulk carriersPassenger ferriesOffshore supply vesselsFishing vessels
Certifications:
USCG Type ApprovalIMO SOLAS compliance
Decision Guide: Choose if you need a single device that provides both satellite (406 MHz) and AIS distress alerts, want built‑in GPS accuracy, and require an integrated SART for radar detection. Avoid if your maintenance regime cannot guarantee the five‑year battery replacement schedule or if water‑tightness is a critical concern in harsh environments.
Use Cases: Commonly installed on merchant vessels required to carry EPIRBs under SOLAS, as well as passenger ferries and offshore platforms where rapid AIS detection of a distress signal can significantly reduce rescue time. Also fitted on lifeboats and survival craft for added SART capability.
Orolia (Kannad)
1
Kannad Marine EPIRB Pro
N/A
· Distress Signal (Satellite/Radar)
· 406 MHz GPS‑enabled EPIRB
Frequency mhz
406
Gps
ja
Gmdss
ja
Battery life yrs
10
Common Failures & Inspection Points
- Battery expiry
- Water seal degradation
- HRU corrosion
Service: Extended battery version. Professional marine grade.
Spare Parts: Ersatzteile über Orolia (Kannad) oder zugelassene Vertriebspartner. Lead time: 2-6 Wochen.
Strengths
- Extended 10‑year sealed lithium battery reduces replacement frequency
- Integrated GPS provides accurate location data to SAR satellites
- Marine‑grade housing designed for harsh sea conditions and water‑seal durability
- Full compliance with IMO SOLAS and USCG type‑approval requirements
- Built‑in GMDSS interface enables automatic distress signalling
Weaknesses
- Battery will need replacement after the 10‑year service interval
- Water‑seal degradation can occur over long deployments, requiring periodic inspection
- HRU (hydraulic release unit) corrosion reported in older units
- Higher upfront cost compared with basic EPIRB models
- Limited to vessels that require SOLAS‑type equipment; overkill for small pleasure craft
Typical Vessels:
TankerContainer shipBulk carrierOffshore supply vesselFishing vesselYacht (over 24 m)
Certifications:
IMO SOLASUSCG Type Approval
Decision Guide: Choose if you need a long‑life, GPS‑enabled EPIRB that meets IMO and USCG standards for cargo or offshore vessels. Avoid if budget is tight, the vessel does not require SOLAS‑type equipment, or a shorter battery life is acceptable.
Use Cases: Mandated on SOLAS‑compliant merchant ships, offshore support vessels, and high‑value assets where reliable, automatic distress signalling with precise location is critical; also fitted on lifeboats and rescue crafts for rapid activation in emergencies.
Sailor (Cobham)
1
SP3560 EPIRB
N/A
· Distress Signal (Satellite/Radar)
· GPS‑enabled 406 MHz EPIRB
Frequency mhz
406
Gps
ja
Gmdss
ja
Common Failures & Inspection Points
- Battery life expiry
- HRU mechanical failure
- Lanyard degradation
Service: Part of Sailor GMDSS suite. Annual testing.
Spare Parts: Ersatzteile über Sailor (Cobham) oder zugelassene Vertriebspartner. Lead time: 2-6 Wochen.
Strengths
- Integrated GPS provides precise location data to rescue authorities
- Automatic water‑activated HRU plus manual pull‑cord for redundancy
- Meets IMO SOLAS and USCG Type Approval requirements for all GMDSS‑class vessels
- Long Li‑SOCl2 battery life (up to 5 years) with built‑in self‑test function
- Robust, sealed housing rated for harsh marine environments
Weaknesses
- Battery must be replaced after expiry; failure can render the unit inoperative
- HRU mechanical parts are a known wear point and may need periodic inspection
- Lanyard (pull‑cord) material degrades over time, requiring replacement per schedule
- Higher upfront cost compared with basic 121.5 MHz beacons or non‑integrated EPIRBs
- Annual testing mandatory to retain certification, adding operational overhead
Typical Vessels:
TankerContainer shipBulk carrierOffshore supply vesselPassenger ferryFishing vesselYacht (over 24 m)
Certifications:
IMO SOLAS Chapter VUSCG Type ApprovalDNV GL Class approval
Decision Guide: Choose if the vessel must comply with SOLAS/GMDSS, needs a 406 MHz beacon with precise GPS location, and can accommodate periodic battery replacement and testing. Avoid if the craft is small recreational or cost‑sensitive where a simpler 121.5 MHz beacon would suffice.
Use Cases: Deployed on commercial cargo ships, offshore support vessels, and larger yachts to provide rapid global distress alerts with exact coordinates, ensuring compliance with international safety regulations during long voyages and in remote waters.