THE PERSIAN GULF I77 



coral, and even when the cut is too small to be noticed, then these 

 poisoned darts enter the flesh and the ulcer soon follows. Stout 

 boots alone were insufficient to arrest the complaint : stout leg- 

 gings would also be required by the surveyors if they were to 

 remain immune while working on the coral reefs. 



On 2nd May, 1949, Challenger left Bahrein for the last time, 

 having spent three surveying seasons in the Persian Gulf. She had 

 surveyed an area of many hundreds of square miles and had located 

 a new deep-water oil port and the necessary approach channels 

 leading from the centre of the Gulf to the desolate shores of 

 Qatar, which, owing to the development of the oil wells, were 

 moving rapidly from obscurity to the limelight of strategic im- 

 portance as each month passed. In addition her boats had surveyed 

 the harbours of Umm Said, Doha and Khor Shaqqiq as well as 

 assisting in surveying the barge routes froin Bahrein to the oil- 

 fields through the Dohat as Salwa, along which the mass of 

 material for the building of the refinery and the oil township was 

 now being carried. 



Much of the offshore work in the last Gulf season was completed 

 with the use of radar, for a suitable set had been fitted during the 

 ship's last refit at Gibraltar. Radar targets affixed to the floating 

 beacons allowed fixes to be obtained regardless of the visibility. 

 But it was still the early days of radar surveying and there were 

 many frustrations and breakdowTis of the apparatus and then the 

 traditional methods once again came into their own. 



