[Digital (406 MHz) Beacons] Resolution or response to registered beacons is very swift. SAR response can be activated within approximately 10 minutes of beacon activation (and GEOSAR detection) if distress is evident. Unregistered beacons can usually be responded to after only 1 LEOSAR satellite pass; after two passes, response is immediate. [Analog (121.5 MHz) Beacons] 
SAR response to anonymous beacons can be delayed 4–6 hours, and as much as 12 hours.[26]