[RedNifre]

It works great for zero dimensional displays that are far away in brought daylight. For example, the Chaos Computer Club used to hack some rental bikes which had an LED that indicated whether the bike was available or not and the hacked bikes would flash "CCC" in morse code, so you could easily identify the hacked bikes from a distance.

I'm not sure about audio morse though, I'd guess voice would be better in all cases there.

[SiVal]

It's not. Combine a loud emergency whistle with Morse Code, and you have the ability to signal without any electric power over much longer distances than voice.

[julian_t]

For years the only Morse I knew was how to use a whistle to send SOS. Maybe it's time to learn a few more letters...