_Hurricane Warnings._—Two red flags with black centers, one above the other, displayed by day, or two red lights with a white light between, displayed by night, indicate the expected approach of a tropical hurricane, or one of the extremely severe and dangerous storms which occasionally move across the Lakes and northern Atlantic coast. These warnings are displayed at 219 Weather Bureau stations on the Atlantic and Gulf coasts of the United States, and at the following places in the West Indies: Basseterre, St. Kitts; Aguadilla Central, Aguirre Central, Arecibo, Arroyo, Fajardo Playa, Guanica Central, Humacao Playa, Luiza (Canovanas Central), Mayaguez Playa, Ponce, San Juan, and Vieques Island, Porto Rico; Kingston, Jamaica; Puerto Plata, San Pedro de Macoris, and Santo Domingo, Haiti; Roseau, Dominica; St. Thomas, Virgin Islands of the U. S. A.; Grand Turk Island, Turks Islands; Swan Island; and Habana, Cuba. NOTE.—The Weather Bureau stations at Cape Henry, Virginia, and the Philadelphia Maritime Exchange Station at Delaware Breakwater are equipped for day and night communication with passing vessels. The International Code is used by day and the Morse Code, flashlight, by night. Messages to or from vessels will be forwarded to destination. [Illustration: SMALL CRAFT] Moderately strong winds are expected A red pennant indicates that moderately strong winds that will interfere with the safe operation of small craft are expected. No night display of small-craft warnings is made. =5.= U. S. SUBMARINE WARNING FLAG [Illustration] 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. [Illustration] =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. [Illustration] =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.