olemus
ametlikult tunnustatud appikutsemärguanne

Merriam-Webster:
: a message that one is in danger
// The pilot sent out a distress signal before the plane crashed.

ülevaateid
https://en.wikipedia.org/wiki/Distress_signal

https://en.wikipedia.org/wiki/Mayday

https://www.msq.qld.gov.au/Safety/Distress-signals

https://www.endeavour-sailing.co.uk/training-information/safety/international-distress-signals

https://www.boatsafe.com/distress-signals/