(1) RADIO NAVIGATIONAL WARNINGS 33 thus; 298°21′+180°-478°21′ or 118°21', which true bearing should be laid off from the plotted position of Nantucket Shoals Lightship. 26 32 29 24 31 37 43 49 25 32 38 44 26 33 39 27 39 46 34 41 28 35 42 30 38 45 53 60 54 62 40 48 56 33 41 49 57 64 72 65 42 50 59 67 31 36 41 38 43 34 39 45 35 41 47 46 48 49 51 51 53 54 56 58 9 18 26 35 44 53 38° 9 18 28 37 46 39° 9 20 30 43° 10 20 44° 10 11 21 32 54 63 55 65 45° 46° 11 48 60 72 84 96 108 120 132 144 156 168 180 192 204 216 228 240 146 158 170 182 194 206 218 231 243 61 73 85 97 109 61 74 13 25 38 50 63 223333 25 38 26 39 52 65 78 91 104 117 130 172 184 197 209 221 233 246 174 187 199 211 224 236 249 176 189 201 214 226 239 252 178 191 204 216 229 242 254 180 193 206 219 231 244 257 143 156 169 182 195 208 221 234 247 260 165 72 74 75 77 54 65 88 121 133 86 98 111 123 135 147 160 87 100 112 124 137 149 162 75 88 101 113 126 138 151 164 64 76 89 102 115 127 140 153 51 64 77 90 103 116 129 141 154 167 121 99 110 62 67 70 73 76 72 79 82 89 84 87 90 95 103 111 98 106 114 101 109 117 108 117 102 111 120 104 113 123 132 142 106 116 125 135 145 108 118 128 138 148 110 120 130 113 123 133 143 153 93 100 108 112 102 109 116 123 129 136 106 113 120 127 134 141 109 116 124 131 138 145 113 120 127 135 143 150 116 124 131 139 147 155 119 127 135 143 151 159 123 131 139 147 155 163 126 134 143 151 159 118 125 131 168 129 103 112 120 172 164 174 138 149 76 86 97 108 119 129 140 151 162 66 77 132 143 154 165 In general, radio broadcasts of navigational warnings contain information of importance to the safety of navigation, such as the position of ice and derelicts, defects and changes to aids to navigation, advice about mine fields, etc. In the United States, radio navigational warnings are compiled by the Hydrographic Office, Navy Department, and by the Bureau of Lighthouses, Department of Commerce. Those issued by the Hydrographic Office commence "Govt. Hydro." and end "Hydro"; those issued by the Bureau of Lighthouses commence "Govt. USLHS" and end "United States Lighthouse Service." Broadcasts frequently include warnings issued by both offices. Scheduled broadcasts of navigational warnings are given in the Hydrographic Office Publication No. 205, Radio Aids to Navigation; a summary of such schedules is included in a sheet issued from time to time by the Hydrographic Office listing broadcasts of United States naval radio stations. Major hydrographic broadcasts, generally covering the Atlantic and Gulf coasts of the United States, are sent out daily by Washington through Arlington (NAA) and Annapolis (NSS). Local broadcasts, for particular areas, are made from stations listed below. Emergency broadcasts are made immediately upon receipt of information regarding imminent dangers. Such emergency broadcasts are repeated hourly for a period of 12 hours or until superseded. The masters of every ship, which meets with dangerous ice, a dangerous derelict, a dangerous tropical storm, or any other direct dangers to navigation, should communicate the information, by all the means of communication at their disposal, to ships in the vicinity and also to the competent authorities at the first point of the coast with which they can communicate. Station Boston, Mass. (NAD). New York, N. Y. (NAH). San Juan, P. R. (NAU). Local Hydrographic Broadcasts Area covered by local broadcast South of Lat. 45°00′ N. and north of Point Judith and Nantucket Shoal Lat. 42°00′ N. to Lat. 38°30′ N. Coast of Florida east of Long. 85°00′ E. (except east coast north of Lat. Caribbean Sea north of Lat. 15°00′ N. and West Indian waters generally. Gulf of Mexico. MEDICAL ADVICE BY RADIO Arrangements are made in various countries whereby mariners of all nationalities may obtain medical advice by radio. Requests for medical advice of an urgent nature should be preceded by the urgent signal in order to give them priority over all other radio traffic except distress communications. The International Code of Signals, 1931, contains a medical section. By use of this code in communicating with foreign stations, difficulties of language may be avoided. The case-stating system in this medical section gives the nature of the information which should be included in the request for medical advice. Whether the message is to be sent in code or plain language, it is recommended that the mariner read this section before preparing his message. Free medical advice, by radio may be obtained direct from the following stations of the United States Public Health Service. United States governmental and commercial radio stations will transmit free messages addressed to any of these stations. In order to avoid confusion and to make the practice uniform, replies will be signed "Marine Hospital No. -", or "Public Health Service Relief Station No. -", as the case may be. These hospitals and relief stations have copies of the International Code of Signals, 1931, for (1) MEDICAL ADVICE BY RADIO 35 use in communicating with ship masters who are unable to use the English language. ATLANTIC COAST: New York, N. Y., United States Marine Hospital. GULF OF MEXICO: Key West, Fla., United States Marine Hospital. Port Arthur, Tex., United States Public Health Service Relief Station. Galveston, Tex., United States Marine Hospital. Coastal stations operated by the Radiomarine Corporation of America offer free medical message service to ships. The messages are sent to the nearest United States marine hospital, or in some cases where there is none in the vicinity, to private physicians. No radio charges are made on such messages when they are prefixed "DH Medico." Stations of the Radiomarine Corporation are listed below: Chatham, Mass. (WCC). Chatham, Mass. (WIM). Chatham, Mass. (WCM). New London, Conn. (WSA). Brooklyn, N. Y. (WNY). Tuckerton, N. J. (WSC). The United Fruit Co., Tropical Radio Telegraph Co., and affiliated companies have established a free medical service which is available to ships. Mariners desiring to avail themselves of this service should use whichever of the following addresses is appropriate: UNIFRUITCO Miami (Fla.). UNIFRUITCO Preston (Cuba). TELARAILCO (Tela, Honduras). TRURAILCO (Truxillo, Honduras). UNIFRUITCO Almirante (Panama). In addition to the above, all passenger steamers of the United Fruit Co. carry doctors, and free medical advice may be obtained from any of them by addressing a radiogram to "Ship's Doctor”, followed by the name of the steamer. In cases of emergency, free medical advice may be obtained by ships at sea by radio from the Panama Canal, through the radio stations at Gatun, Balboa, or Cape Mala. Such message should be addressed: "Govt. C. B., Medico, Pancanal", state briefly and clearly the symptoms to be treated, and be signed by the master. Medical advice radiograms must be checked and sent "DH Medico." Such radiograms will be given preference over all messages except SOS calls. Medical advice will be phrased in language intelligible to the layman. Complete details relative to the service furnished by all companies is published in the manual, Ship Sanitation and First Aid, issued by the Seaman's Church Institute of New York. This manual contains diagrams and a list of symptoms to be considered in preparing messages. In addition to the above, current information on this subject can be secured by referring to the Hydrographic Office Publication No. 205, Radio Aids to Navigation. WEATHER Fog. From November to April, inclusive, fog may occasionally be encountered near the coast at any point between San Carlos Bay and the Rio Grande. It is most dense in the vicinity of the harbor entrances, and the prominent points, such as Cape San Blas. Usually southerly winds bring it in, and northerly winds clear it away. See also the meteorological tables in the appendix. The following table shows the number of hours per month that the fog signals were operated at the stated light stations on the Gulf coast of the United States during 1924. Although similar data are not available for a later date, the table indicates the possible monthly distribution of fog which may be an important consideration. The right-hand column in the table below gives the yearly averages for a number of years prior to 1929. Northers. From November to April, northers blow from northwest and north with considerable violence; their duration is from 1 to 4 days, the latter being exceptional. They occur more frequently, and are more strongly marked, along the coast of Texas than eastward; but their general characteristics are alike all over the Gulf of Mexico. The indications of an approaching norther are invariably a slightly falling barometer, generally not more than 0.20 inch, and lowering temperature; it begins with a violet squall, during which the temperature may drop 20° in 10 minutes. After the first squall the wind gradually increases to a fresh gale, but does not reach its maximum velocity until after the barometer has begun to rise, and it will generally blow with full force for at least 24 hours. Sometimes the temperature drops to as low as 18° F. Some northers are dry-that is, unattended by precipitation-others are attended by cold rain, that may turn into sleet or snow. Northers along the Gulf coast are not dangerous for large vessels, but small vessels are sometimes blown offshore. They affect, however, the depth of water in the harbors and on the bars by blowing December Total 1924 Yearly aver age (1) STORM WARNINGS 37 the water offshore, in some cases lowering the water by as much as 4 feet. This should be borne in mind by vessels attempting to enter the harbors on the Gulf coast, during or soon after a norther. Currents in narrow channels and in the Gulf are also greatly affected by northers. Southeast gales are dangerous to shipping along the Gulf coast of the United States, westward of Apalachee Bay. They may occur at any time of the year, but are most dangerous in winter and early spring. During a heavy southeaster, the bars at the entrances to the harbors are made impassable for deep-draft vessels, on account of the heavy sea which breaks in depths of about 4 fathoms. The usual local indication of a southeaster is a breeze freshening at eastnortheast or east, and hauling southward, accompanied by a falling barometer, a rising temperature, and an increasing swell. The lowest reading of the barometer is usually reached immediately after the wind gains its maximum velocity at southeast. When the wind hauls southward of southeast it is an indication that the gale is breaking, which is usually followed by heavy squalls; as it hauls westward of south, first rain squalls, and then clearing weather, may be expected unless, as is sometimes the case, the southeaster be followed by a norther. Southeast gales raise the water in the harbors along the Gulf coast, in some cases, to a height of 6 feet above the normal. Along the western coast of Florida, from Cape Romano to Apalachee Bay, southeast gåles are not so dangerous to shipping; vessels can anchor in shoal water under the lee of the land and hold on until the gale abates. STORM WARNINGS Storm warnings are displayed by the United States Weather Bureau at numerous places on the coasts of the United States and the Great Lakes. Small-craft warning.-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. Northeast storm warning.-A red pennant above a square red flag with black center displayed by day, or two red lanters, one above the other, displyed by night, indicate the approach of a storm of marked violence with winds beginning from the northeast. Southeast storm warning.-A red pennant below a square red flag with black center displayed by day, or one red lantern displayed by night, indicates the approach of a storm of marked violence with winds beginning from the southeast. Southwest storm warning.-A white pennant below a square red flag with black center displayed by day, or a white lantern below a red lantern displayed by night, indicates the approach of a storm of marked violence with winds beginning from the southwest. Northwest storm warning.-A white pennant above a square red flag with black center displayed by day, or a white lantern above a red lantern displayed by night indicates the approach of a storm of marked violence with winds beginning from the northwest. Hurricane, or whole gale warning.-Two square flags, red with black centers, one above the other, displayed by day, or two red lanterns, with a white lantern between, displayed by night, indicate |