its marked variations in position and quantity from year to j'ear, the 

 more efficient a patrol it will be possible to maintain, and the greater 

 will be the value of the service to shipping in general. The scientific 

 and oceanographic work, being supportive and secondary in impor- 

 tance to the practical scouting and advisory work, however, was so 

 arranged as not to hamper ice scouting and trailing. 



The Mojave inaugurated the 1928 patrol on March 21, and from 

 that date until the service was discontinued by a dispatch from Coast 

 Guard headquarters on June 22, either that vessel or the Modoc was 

 continually on guard in the ice regions. 



Most of the vessels that ply between Europe and the United States 

 and Canada do not follow the shortest route. That would be the 

 great circle track and it would lead them, when plying between most 

 ports, close past Cape Race, Newfoundland. On account of the well 

 recognized ice menace, vessels have for many years followed estab- 

 lished tracks, or lanes, that are shifted from time to time as the limit 

 of the ice advances and recedes. 



Figure 1 shows the approximate location of the different steamer 

 lanes, and the explanation of the diagram shows when the different 

 tracks are normally used. It is comparatively infrequent that the 



Explanation of Figure 1 



A, B, and C, are routes to and from New York. 



D, E, F, and G, are routes to and from Canadian ports. 



Eastbound tracks are full lines. 



Westbound tracks are dashed lines. 



For fuller information relative to the North Atlantic lane routes see the special 



track charts published by the United States Hydrographic Office and by the 



British Admiralty. 

 Inclosed area between tracks E and B about the Tail of the Grand Banks shows 



where the distribution of the ice usually keeps the ice patrol vessel. 

 Normal periods different tracks are used: 

 A, eastbound. March 25 to July 7. 



A, westbound. April 1 to June 30. 



B, eastbound. February 1 to March 24, and July 8 to August 31. 



B, westbound. February 1 to March 31, and July 1 to August 31. 



C, eastbound. September 1 to January 31. 



C. westbound. September 1 to January 31. 



D. February 15 to April 10. 



E. April 11 to May 15 or until Cape Race Route is clear of ice, and Dooember 



1 to February 14. 



F. May 16 to opening of Strait of Belle Isle, and to November 30. when not 



using Belle Isle route. 



G. From opening of Strait of Belle Isle to November 14. 



Above so called normal periods were taken from United States 

 Hydrographic Office chart of North Atlantic steamship routes. 

 A tracks were not used at all during 1928. 

 B tracks were used from April 14 to September 1. 

 C tracks were used between United States and Europe throughout rest of year. 



