What conditions do PLBs not work in?

Conditions where PLBs work and don’t work

Always have a backup plan. Mila Kunis

PLB sends a message using satellites orbiting the Earth, you will get the best result if you are in an open area with a clear view of the sky. Best to be clear of dense tree canopy, buildings, mountains, and vehicles. The aerial must be vertical pointing towards the sky, preferably with 180 degrees or more of visibility. Always follow the instructions on the PLB.

PLBs do not work in caves and deep narrow gorges
They will be slow to signal an emergency in narrow canyons and gorges with a limited view of the sky and not work at all in places such as caves. As much as possible, position the PLB where it can ‘see’ as much of the sky as possible.

Detection of distress signals can also be affected by bad weather such as lightning and strong wind, and rescue operation delayed due to poor visibility at night. So if you are in a narrow gorge such as a Blue Mountains canyon at night in bad weather, you may well have to wait a long time for the rescue crew to reach you, even if your signal is detected. In such situations, if you are in a group, it may be more effective to send somebody out to raise the alarm as well.

Using a PLB anywhere near water
If using a PLB near water (including river crossings) it is highly recommended that you purchase one that floats (either self buoyant or aided by external flotation pouch) and is fully waterproof. PLBs sold in Australian and New Zealand must meet AS/NZS 4280.2.2003, which requires that the PLB must be waterproof and capable of floating.

If purchasing a waterproof PLB, check that it has a waterproof aerial as some PLBs, while waterproof, don’t have a waterproof aerial and do not work as effectively when activated in the water.