The submarine distinguishing and warning flag is hoisted on the tender or parent ship of United States submarines to indicate that submarines are operating in that vicinity. It consists of a rectangular red flag with white center on which is the profile of a torpedo in black. Launches accompanying submarines also fly this flag.
Vessels seeing this signal should give the escorting vessel a wide berth and keep a good lookout for submarines.
6 EXPLANATION OF SYMBOLS.
DERELICTS AND WRECKS.—The name of the vessel is given, if known, and the symbol in red represents the reported rig and condition at the date set opposite to the position. The successive positions in which the derelict was sighted are joined by lines of dashes and the corresponding dates are indicated.
DRIFTING BUOYS.—These are shown in red color. The date when sighted is also given in red.
ICEBERGS FIELD ICE.—These symbols with date represent ice of previous month. When numerous bergs are reported by one vessel along a given track the date and position of the first and last one only are graphically shown, and the number of bergs is written on a line joining them.
