What communication device should I take with me on a bushwalk to a remote area? What about a satellite or mobile phone? Why should I replace my EPIRB with a PLB? What alternatives are there to a PLB? What are the advantages and disadvantages of a SPOT ?
Traditionally, when walking in a remote area, you always walked with a least three others so that if one person sustained an injury, two of the group could go for help, while the other looked after the injured person. With the availability of satellite technology and sometimes simply a mobile (cell) phone, it is possible to seek help from where the injured person is located rather than have to walk to the nearest road or homestead.
Most people are familiar with the mobile phone, which has excellent range if there is line of sight. This means that sometimes, even in supposedly remote areas, there will be good reception from a mountain top or ridge line. If you are within range of a tower used by your carrier then your family of friends can contact you too; it is not just one way. In an emergency, by dialling 000 or 112 your phone can access the tower of a competitor and effectively roam between carriers depending on which has the best signal.
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Satellite phones can achieve the same as a mobile phone, but even when there is no line of sight or the distance from the nearest tower is too great. Both the phone itself and the plan are expensive, so for many this is not an option. They do however offer the advantage that your family or friends are able to get in contact with you if they wish as it allows two way communication.
Many bushwalkers had been using an EPIRB ( Emergency Position Indicating Radio Beacon) which until February 2009 provided the extra layer of security in remote areas, but this had a very poor accuracy*, as low as 20 km, low power and time lag in activation. The alert frequency from the EPIRB (121.5 MHz) is no longer monitored by rescue authorities so they are now useless and should be disposed of carefully. Battery World provides such a service free of charge.
This has now been replaced by a PLB, which operates at two frequencies, the higher 406 MHz to give the satellite alert and the lower 121.5 MHz provides the final homing signal for the search aircraft. The more expensive models have a GPS in-built which means that not only can an alert be given, but that the exact location of the injured or lost person can be given. This is a great improvement and dramatically reduces the search time as the location is given to within 100m. Without a GPS, they have an accuracy of about 5 km. They must be registered so that emergency authorities can access details of next-of-kin to check that it is not a false alarm. They also have access your route plan if you have registered it. PLBs only offer a one way service: user to emergency rescue services. They can be hired form a variety of sources depending on location.
* Communications for Bushwalkers Rik Head Bush Search and Rescue Victoria (Version 1.0 March 2009) pdf
Satellite Personal Tracking Systems
SPOT gen3 is an example of a handheld system which is capable of sending your position by satellite to a list of friends and can also be displayed on Google maps. If you need help, a message can be sent using a preset list of custom messages. In a life threatening emergency, there is a SOS button which sends a message and is relayed by GEOS to the AMSA RCC as for a PLB.
- Works were you mobile (cell) phone has no reception
- Allows customised messages to friends
- Allows automatic tracking of your position at regular intervals
- Relatively low cost purchase price
It is a one way system like the PLB, with no messages from friends possible. There is a yearly subscription fee in addition to the purchase price. Currently the basic fee is USD $115 and the tracking option fee an additional USD $49.99 Purchase price is less than AUD $200 with free shipping.
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