on the 30-fathom shoal near the southeastern edge of the banks, 

 the greater number continued to drift southward along the eastern 

 edge of the banks and spread southeastward from the Tail of the 

 Banks toward the vicinity of 41 ''30' N., 46°30' W. The presence 

 of bergs in these southerly positions menaced the safety of vessels 

 navigating the fog-bound waters just south of the banks and ship- 

 ping was advised to shift its routes from track B to track A effective 

 12 June. See figure 38 for a plot of bergs and growlers reported 

 during June. 



July 



Except for local coastal shipping along northern Labrador and 

 northward off Hudson Strait, the field ice had receded to such ex- 

 tent by the first of July as no longer to constitute a menace to 

 shipping. By mid-July only a few scattered remnants remained 

 south of Hudson Strait. For details concerning ice conditions 

 north of that area refer to the discussion of the Canadian Arctic 

 area. 



The bergs that had endangered track B during June had melted 

 and disappeared by early July. Reconnaissance by planes and search 

 by the surface patrol vessel indicated that ice no longer made track 

 B hazardous and the return to those routes was advised on the 14th, 

 the shift to occur immediately in the case of the west-bound track 

 and after a delay of 7 days for the east-bound traffic. With the 

 exception of the growler reported on the 7th at 45° 10', 45° 12' and 

 the bergs along the Newfoundland coast, no ice was reported during 

 July in positions south of the 47th parallel. Aerial observations 

 of that area were limited during the month by weather conditions 

 and the absence of reports cannot be considered conclusive evi- 

 dence that no bergs drifted into the area. Many bergs were present 

 in the area along the northern edge of the Grand Banks late in the 

 month and it is estimated that approximately 109 had drifted across 

 the 48th parallel during the month. See figure 39 for a plot of 

 bergs and growlers reported. 



August 



Several bergs drifted on southward during early August reach 

 ing as far south as the 45th parallel. A few of them remained 

 in the area east of the slope of the banks until after 20 August. 

 The absence of ice in the southern Grand Banks area had made the 

 shift to track C possible and west-bound traffic had been advised 

 to shift to track C on 1 August, the east-bound shift to be effective 

 on 8 August. While the positions of these bergs in mid-August 

 were not in immediate proximity to the effective track, in the ab- 

 sence of definite knowledge of the then existing current pattern, 

 the surface patrol vessel was detained in the area until 26 August 

 when air search supplementing this surface search had indicated 



94 



