The minimum response time for a 406MHz beacon can be up to 90 minutes before a search is even initiated and this is totally dependant on the person carrying the unit being able to switch it on
a difficult task if youre unconscious or in Cold Shock response!
The minimum Alert time for a fully automatic Sea Marshall® 121.5 MHz PLB, to a boat fitted with a suitable alarm/receiver, is approx 15 seconds.
406 MHz PLBs are not fully automatic
useless if you are knocked unconscious.
406 MHz PLBs must be registered to each person and cannot be exchanged amongst crew members.
Other systems transmitting on frequencies away from 121.5 MHz cannot be tracked by the Search and Rescue Authorites. Which means that if the person in the water floats out of range of the receiver on the boat then the chances of them being located are dramatically reduced
the search will become visual only which is like looking for a needle in a haystack.
Proximity Alerting systems, working on frequencies away from the SAR homing frequency, carry the risk of a crew member falling over board and becoming trapped next to the vessel, in a line or net perhaps, and the alarm not being raised because the person has not gone out of the monitored area resulting in drowning. Also such systems are operating on frequencies that cannot be tracked by the Search And Rescue Authorities.
