[QUE] Seeking info on flares shot by sinking ships

[mkubani]

Hello guys,

I would like to ask you about some information regarding flares used by doomed ships that were hit either by enemy subs or enemy planes.

Was it a common practice by warships and merchants to shoot such flares? If yes, what was the colour? Red? White?

As for the lifeboats/survivors, would they also send some visual signal to rescue float planes? What kind, please?

Thanks a lot for the information.