CHAPTER I. GENERAL INSTRUCTIONS 

 1000. TIME OF OBSERVATION 



1010. SYNOPTIC REPORTS. Cooperating ships are requested to make and 

 record synoptic weather observations at the hours of 0000, 0600, 1200 and 

 1800 Greenwich Civil Time (GCT) while at sea. If it is not possible to make 

 four observations daily, as many observations as convenient should be taken. 

 Observations should be made in sufficient time for delivery to the Radio 

 Officer by the synoptic observation time. 



1011. Weather observations should be made to within 25 miles of the 

 coast except in sparsely traveled areas. When underway along the coasts 

 of Central America and the U. S. Pacific Coast (including Alaska but not 

 the Inland Passage), observations should be taken and reported regardless 

 of the distance from shore. 



1020. SPECIAL REPORTS. In accordance with the International Conven- 

 tion for Safety of Life at Sea, masters of all ships are requested to take 

 special weather observations and report by radio when tropical or severe 

 storms are encountered. These reports are not limited to synoptic hours 

 but may be reported regardless of hour. 



1021. When a tropical storm is reported, the Weather Bureau may 

 broadcast requests for special radio weather reports from all ships in the 

 vicinity of the storm. These requests will always include instructions rel- 

 ative to the time and frequency of the reports and the address to which the 

 reports should be sent. 



1100. SHIP'S WEATHER OBSERVATIONS- FORM 615-5 



1110. GENERAL. All weather observations made at sea will be re- 

 corded on Form 615-5, Ship's Weather Observations. To assist coding 

 weather data, a complete international Ship's Weather Code and Cloud Code 

 Chart are included with each pad of Form 615-5. The individual sheets, 

 when used, may be torn off along the perforation and stored in the back of 

 the folder until the end of the trip. 



A new page of Form 615-5 will be started: 



(a) For the first observation of a new month. 



(b) At the beginning of each voyage. 



(c) Upon sailing from one octant to another. 



(d) Upon sailing from one ocean to another. 



1120. ENTRY OF DATA. Enter the observations as legibly as possible, 

 using a well sharpened black pencil or a pen. The data should be entered in 

 the columns appropriate to them as indicated by the column headings. 



