VIII 



Iceland 



THE War was very near as Challenger hurriedly completed 

 her refit at Portsmouth, and on 2^th August the officers 

 and men on leave were recalled from their homes so that 

 the ship might sail for her war station on the following day. 

 From the Humber to Dover the waters of the east coast of 

 England are comparatively shallow and encumbered by numerous 

 sandbanks, and it is only by navigating the channels between them 

 that ships can safely sail along the coast or enter the Thames 

 Estuary and the other ports of East Anglia. With many of the 

 navigation lights ashore extinguished or considerably reduced in 

 visibility as they would be on the outbreak of war, vessels would 

 have great difficulty in navigating those channels. The shallow- 

 ness of the waters makes the mining of ships off the east coast a 

 comparatively simple task for the enemy, so that in order to 

 reduce the amount of water to be swept daily by our limited 

 number of minesweepers it had long since been planned to 

 restrict navigation to war channels, which were to be marked 

 by lighted buoys every three miles or so to ensure that the 

 convoys kept to the swept and navigable water. 



The accurate positioning of these buoys was, therefore, of im- 

 mediate importance and was an exacting task, many miles at sea 

 off the flat, featureless coast of East Anglia. It was Challenger^s 

 first war-time duty to sail along the war channels, and, using taut- 

 wire measurements and shore fixes where possible, to fix the 

 proposed position of each war channel buoy and mark it with 

 a temporary light buoy. Trinity House, who maintain the lights 

 and the buoys around the coast of England, would later lay the 

 large light buoys anchored by their six-ton clumps in each of 

 these marked positions. Thus, in these anxious days just before 

 the outbreak of war. Challenger, her gleaming white sides and 

 yellow funnel now painted a uniform grey, was slipping out of 

 Harwich in the dark hours before the dawn, followed by the 



83 



