After this date, beacons transmitting on this frequency will only be used for localised homing, so for the most part they are redundant.

RYA Cruising Manager Stuart Carruthers explained: “Nowadays modern beacons transmitting on 406 MHz offer many advantages over analogue 121.5/243 MHz beacons. “With a 406 MHz beacon, the position of the distress can be relayed to rescue services more quickly, more reliably and with greater accuracy. These will not be affected by the change.”However, some of the older devices transmit on 121.5/243 MHz only and it is these that will become redundant as a means of emergency alert following the decision to discontinue monitoring this frequency.

“The important thing is that people check their beacons and make sure that they are not redundant. From a safety point of view, this is paramount,” he added.

The frequency on which your EPIRB transmits should be clearly marked on the casing so it’s an easy matter to check.

Cospas-Sarsat, the organization that runs the satellite system supporting these alert devices, has decided to cease satellite processing following recognition of the limitations of the 121.5/243 MHz beacons and the superior capabilities of the 406 MHz alerting system.

In addition, only about one alert out of every fifty on the analogue system was a genuine distress.This has a significant effect on search and rescue resources and was a major factor in the decision to discontinue the service.

However, 121.5/243 will continue to provide a short-range homing signal once an initial call for assistance has been made and rescue services are in range of the casualty.

For further information the MCA’s Marine Guidance Notice gives you a full overview of the changes.