90 CHALLENGER 



outward bound to harry our shipping on the wide oceans. These 

 fjords were Httle surveyed, and H.M.S. Franklin, another naval 

 surveying ship, had recently sailed north with the forces occupy- 

 ing the Faroes and was now carrying out a survey of Scaale 

 Fjord, the fine landlocked anchorage in those islands. 



It was now thought at Scapa Flow that Lieutenant- Commander 

 Prien had entered in his U-boat to sink the Royal Oak by one of 

 the four eastern channels. These entrances had been considered 

 to be effectively blocked by the sinking of a number of old 

 merchant ships both before and since the outbreak of war, but 

 now it seemed that there were one or two small remaining gaps, 

 through which flowed the swift tidal streams, where there was 

 just sufficient room for a submarine to pass if piloted with 

 supreme skill. Only a solid causeway across these four entrances 

 would absolutely ensure no repetition of Prien' s masterly feat of 

 seamanship with disastrous effects upon our Fleet within. But to 

 build such a causeway and block the very strong tidal streams 

 running here might so increase their force in the two main 

 entrances of Hoxa and Switha Sounds that it would be impossible 

 to maintain a boom there. To test this possibility before building 

 the causeway a tidal model of the Flow was to be built and for this 

 an accurate tidal survey of the existing Eastern Channels was 

 required, and it was for this purpose that Challenger sailed from 

 Shetland to Scapa; but when she reached there orders came to 

 transfer these instructions to Franklin, newly arrived from Faroes, 

 while Challenger was to proceed without delay for surveys in 

 Iceland. Within a few hours of arriving in Iceland the fleet net- 

 layer, H.M.S. Guardian, which was to lay the net defences across 

 the mouth of Hvalfjord, had struck an uncharted rock and could 

 do no more. Good charts of the Icelandic fjords were required 

 and Challenger must make them as fast as she could. 



Surveying ships do not often operate in company and seldom 

 do they meet each other, but when they do there is much to 

 discuss and a reunion party always results ; the officers of both 

 ships, many of whom will have served together on other stations 

 years ago, will speak of the eccentricities of former mess-mates, 

 the capacity of their present Captains to force the pace of the 

 work, and recall perhaps a hundred amusing incidents of the past 



