[I seem to have overlooked this one at the time ]

Air Canada Flight Diverts to Find Missing Yacht

Passengers aboard an Air Canada 777 diverted to look for a distressed yacht near Sydney, Australia, checked out a GPS location from an emergency beacon at 4,000 ft altitude.

"The crew and several passengers spotted the yachtsman’s signal mirror"

Edited by rafowell (02/22/21 05:14 AM)
Edit Reason: Added missing space in title
A signal mirror should backup a radio distress signal, like a 406 MHz PLB (ACR PLB) (Ocean Signal PLB)