Here are the standards regarding distress signals in 1912:
Daytime
(1.) A gun or other explosive signal fired intervals of about a minute.
(2.) The international code signal of distress indicated by NC.
(3.) The distant signal, consisting of square flag, having either above or below it a ball or anything resembling a ball.”
(4.) The distant signal, consisting of a cone, point upward, having either above it or below it a ball or anything resembling a ball.
(5.) A continuous sounding with any fog-signal apparatus.
” - This is purely a code signal, and is not one of the signals of distress given in the Rules of the Road, the needless exhibition of which entails penalties upon the master of the vessel displaying it.
At night;
(1.) A gun or other explosive signal fired at intervals of about a minute.
(2.) Flames on the vessel (as from a burning tar barrel, oil barrel, etc.).
(3.) Rockets or shells, throwing stars of any color or description, fired one at a time at short intervals.
(4.) A continuous sounding with any fog-signal apparatus.