WHAT'S A VPIRB?

A VPIRB (VHF Position Indicating Radio Beacon) is a Maritime Survivor Locating Device (MSLD), specifically designed to alert the parent vessel that they have lost one of their crew overboard.

In most man overboard (MOB) situations, the vessel from which the person came from is in the best position to render immediate assistance.

A VPIRB is equipped with an internal GPS receiver, and uses VHF DSC (Digital Selective Calling) and synthesised radiotelephone (voice) transmissions to broadcast this GPS position to all vessels and shore stations in range.



DSC is a very suitable technology for a MSLD, as it allows alerting of both the parent vessel, and all other DSC-equipped vessels in the immediate vicinity.

Personal Emergency Position Indicating Radio Beacons (EPIRBs) have saved many thousands of lives over the years; however they rely on shore infrastructure to process and then re-broadcast an alert message to ships in the vicinity of the person in distress. Depending on the location of the EPIRB, this could involve delays in the order of hours.

A VPIRB activates automatically on contact with water, or it can be manually switched on. It will provide alerting ranges in the order of 2 nautical miles from a typical small boat. Larger vessels and shore stations with higher antennas will receive the distress signal over longer ranges.

At present, there is only one VPIRB model available, the Mobilarm V100 VPIRB.
HOW DOES A VPIRB WORK?

The VPIRB can be automatically activated from the 'armed' position when the device is immersed in water. Manual activation is also possible.

The VPIRB transmits an alert, a unique identity number and the MOB's exact GPS coordinates to all vessels in the vicinity, including the distressed mariner's vessel, as well as to any land-based VHF receivers in range.

The VPIRB automatically sends an initial "Mayday - man overboard" alarm in DSC data message format, using VHF DSC (channel 70), to alert the parent vessel and other vessels that the MOB event has occurred.

As soon as a GPS lock is obtained, typically in under 30 seconds, the distress call is transmitted again with latitude and longitude coordinates, using VHF DSC and in a synthesized voice format on VHF marine channel 16. This is repeated at regular intervals to update rescue personnel with the MOB's current position.
Overview of the VPIRB Rescue Anatomy
Overview of the VPIRB Rescue Anatomy
NOT JUST ANOTHER EPIRB

Conventional marine personal locating beacons such as personal EPIRBs must be manually activated to send any signal - as mandated by regulatory authorities. This may be difficult or impossible to do if a MOB is injured or unconscious. Personal EPIRBs transmit an emergency signal to a remote onshore location, which can introduce unnecessary delay in the recovery of an MOB - greatly reducing their chances of survival.

VPIRBs provide instant notification to a mariner's vessel that a MOB event has occurred, alerting the people who are in the best position to rescue the MOB and ensuring they are deployed as soon as possible.

VPIRBs do not require any additional dedicated receiving base stations, 121.5 MHz directional finding equipment or satellite rental time. With a VPIRB, as long as a VHF radio is onboard, no other equipment need be installed; the VPIRB uses only existing industry-standard VHF marine radio networks.

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