ington, and by the "branch Hydrographic offices at Boston, New York, 

 and Norfolk. 



11. Each patrol vessel will keep a remark book in which will be 

 •entered all data and information concerning the ice that can be 

 •collected. 



12. Each vessel, on being relieved by the other vessel, will 

 deliver to the relieving vessel a copy of each radiogram sent to or 

 received from the Hydrographic Office during the cruise, and a copy 

 of each instruction received from Headquarters by radio. 



13. At the end of each cruise each vessel will forward to Head- 

 quarters a full report in triplicate. These reports should not include 

 any matters of purely ship's business or ship's routine which do not relate 

 to the ice patrol. Each vessel will send these reports direct to Head- 

 quarters and furnish a copy of each report to the other vessel on patrol. 



14. Each vessel will plot on tracing paper used in connection with 

 the appropriate plotting sheet, the positions and extent of the ice as 

 located from time to time. Such data will also be plotted on a dupli- 

 cate tracing paper, and this duplicate will be delivered to the relieving 

 vessel. 



15. If, in order to avoid delay in any emergency, it becomes neces- 

 sary for the junior commanding officer to communicate directly with 

 Headquarters, a copy of each such communication shall be furnished 

 to the patrol commander. 



16. Barometers of patrol vessels must be calibrated by the United 

 •States Weather Bureau before sailing on patrol duty. 



W. E. Reynolds, Commandant. 



Treasury Department, 

 United States Coast Guard, 



Washington, April 21, 1923. 

 To the Commanding Officers of Coast Guard Cutters on Ice Patrol, 1923: 



1. Paragraph 5 of Headquarters' letter of February 9, 1923, is 

 amended to read as follows: 



5. Having located the ice, the patrol vessel will send the following 

 daily radiograms. All times in radiograms will be in 75th meridian 

 time : 



(a) At 6 a. m. and 6 p. m. (75th meridian time) ice information will 

 be sent broadcast for the benefit of vessel's, using 600-meter wave 

 length. This message will be sent three times, with an interval of 

 two minutes between each. 



(&) At 8.30 p. m. (75th meridian time) ice information will be sent 

 broadcast for the benefit of vessels, using 2,300-meter wave length. 

 This message will be sent three times, with an interval of two minutes 

 Ixetween each. 



