ICE OBSERVATION 



The presence of ice is a constant menace to the navigator passing 

 through the ice area. Were the ice stationary very little danger would 

 exist, but its movement being dependent on the ocean currents, the 

 sea, and to some extent on the wind, makes its location very uncer- 

 tain and thus the more dangerous. Every ship speeding through the 

 ice infested areas by night or in the fog plays a game of chance. 

 It is the duty of the patrol vessel to attempt to eliminate the danger 

 by giving each vessel passing through the ice areas all possible in- 

 formation in regard to the set and drift of currents, the set and drift 

 of the ice, and its location at all times. To obtain this information 

 requires considerable cruising and searching for bergs and then after 

 finding them requires trailing them to determine their movements. 

 Trailing a berg gives the patrol vessel an opportunity to study the ice. 



The season of 1925 offered innumerable opportunities to observe 

 the bergs and to experiment wifli them. At one time 169 bergs were 

 plotted on the operating chart and, at that, no berg above latitude 

 50° N. was considered. Considerable time was devoted to experi- 

 menting with mine and gun fire and to observing the melting 

 processes. 



An estimate of the ice situation was made at the beginning of the 

 patrol in an attempt to predict the future ice. The amount of ice 

 and its location has been so variable from year to year, and the 

 source never having been thoroughly observed, there has been no 

 system of ice forecasting developed successfully as yet. Reports 

 indicated at the beginning of the season that Nova Scotia, New- 

 foundland, and Labrador had had one of the mildest winters ever 

 experienced in those areas, that the first part of April was colder 

 than any month during the winter, that no ice except local ice had 

 been seen around Cape Race and in the bays in that vicinity up to 

 April 8. The prevailing winds of the winter had been northwest 

 and northeast, but in the month of March and first part of April 

 had been consistently northeast, and the average temperature for 

 the winter had been 37° F. The ice reported prior to the commence- 

 ment of ice patrol was as follows: 



February 13.— Pan ice (lat. 47° 5' N., long. 49° 27' W.). 



FeVjniary 19.— Heavy slob ice (lat. 48° 35' N., long. 49° 15' W.). 



February 24.— Slob ice (long. 48° 30' N., long, between 48° 50' and 49° 20' W.); 



iceberg (lat. 50° 00' N., long. 46° 25' W.). 

 March 1.— Large berg (lat. 47° 28' N., long. 47° 34' W.). 



March 2.— Two bergs (lat. 48° 34' N., long. 47° 50' W.; lat. 48° 17' N., long. 



48° 43' W.). 



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