ICELAND 89 



trench revealed the triangulation mark (A) cut clearly in its 

 surface so many years before, still marking the exact position in 

 the survey of Great Britain. 



Challenger worked on at Scapa, Kirkwall, again at Port A and 

 at Kyle Akin on the west coast of Scotland. She returned to 

 Portsmouth for a refit in March, but while the refit went for- 

 ward there was little respite for the surveyors, who were 

 occupied with defence surveying in and around Portsmouth and 

 Spithead. In early April the Germans invaded Norway and the 

 'hot' war had begun. This was marked in Challenger by the fitting 

 of two pom-poms on the forecastle and the refit was hustled 

 forward. Many of the experienced men now left the ship and it 

 was with a new crew that she sailed away again, carrying a 

 number of men who had joined the Navy for the duration of the 

 war only and knew no difi^erence between a surveying ship and 

 a destroyer during their first days onboard. The same round of 

 harbour surveys in comiection with controlled mining defences 

 went on — Plymouth, Milford Haven and then to Sullom Voe in 

 Shetland, where work was completed by the end of May. In the 

 Shetlands the Germans were now only 200 miles away across in 

 Norway; an airborne attack against our northern outposts seemed 

 a likely possibility so the boat sounding, coastlining and observing 

 parties were armed with revolvers and rifles. It seemed difficult 

 to believe, as the surveyors walked the sunlit moors of Shetland 

 in glorious summer weather, that in the Low Countries men were 

 fighting and dying while the situation grew more desperate every 

 hour. Once again the junior officers longed to leave surveying 

 and to get to grips with the enemy, but Commander Jenks, 

 sympathising with them though he did, also realised more than 

 anyone onboard the importance of preparing firm defences of our 

 fleet bases and how very soon now they were likely to be tested. 

 Sixteen hours of every day, seven days of every week, he kept 

 the officers and men to their task. Long days of field work were 

 followed by hours of plotting and inking-in the detail, while the 

 dawn saw the boats away for more sounding or observing. 



Britain had at last taken a firm course in Northern Waters, 

 occupying Iceland and the Faroes, knowing how important it 

 would be to use the long, secure fjords of these islands as fuelling 

 bases from which her ships could sail out to intercept the raiders 



