NAUTICAL NOTES. 257 



Anaivilundun and Nadukadu Paars are the most northern, and represent one continuous stretch 

 of rocky groiuid ^rith living coral, coral debris, and weed. The paar is situated on the edge of an overfall, 

 from a 5-fathom plateau to a 7 to 8 fathoms, which is a continuation of the overfall on which the Vankali 

 reef occurs, although the reef ends where the 2-fathom plateau between the reef and the coast terminates. 



The above 5-fathom plateau extends out in a southerly direction from Adam's Bridge , and is 

 formed of mud and fine sand, with patches of living coral and quantities of prawns and shells. The 

 paar itself is formed almost wholly of Turhinaria crater. Massive stony coral is rarely found here. The 

 area of the paar is considerable, being approximately 6 square miles. The average depth is 5 fathoms. 

 There appears no record of oysters maturing or of fisheries on this paar, although the rock where the 

 coral occurs is clean and apjiears suitable for oysters. 



The paar is about 6 miles long and 1 mile broad, and rims in a west-north-westerly direction from 

 Vankali reef, from which it is separated by a 3-mile stretch of sandy bottom, on which the depth of water 

 increases as the Vankali reef is left and the paar is approached. 



6. — Method of Inspection by Divek.s. 



The examination and inspection of the pearl banks is carried out by native divers imder the 

 superintendence of the Superintendent of Fisheries, who also checks and verifies the native divers' reports 

 as to the nature of the bottom by personal inspection in the diving dress. 



The present method of inspection is an improvement on the circular method inaugurated by Capt. 

 Donnan, which latter necessarily left intervening spaces between the circles, to obviate which the present 

 rectangular method has been adopted. The circular method was convenient for prospecting, but for 

 systematic survey and accuracy the rectangular method adopted has many advantages, such being 

 continuity, greater accuracy, and the avoidance of distortion, equahzed labour, and a greater area covered 

 daily ; the courses are straight, and full advantage can be taken of the prevaiUng north «"ind, and finally 

 four areas can be inspected from one central position, which means that the inspecting vessel need only 

 move to a new position every third or fourth day. The latter advantage is a great saving of wear and 

 tear to the Company's vessels. Another advantage of the rectangular method is alinement, which 

 means that lines of positions can be extended to the outside positions with great accuracy ; and a further 

 advantage is that beds of oysters can be, as the paar is, accurately figured and the numbers estimated 

 more nearly. 



The four inspection boats, six-oared whalers, start from the ^^indward side of the area to be 

 inspected, and work across the wind east and west, between the buoys (which are laid down north 

 and south, east and west), in such a manner as to direct the boats on their east and west course and 

 prevent their getting out of position. Each coxswain is provided with a chart on which the result of 

 each dive is recorded with the soundings. 



The inspection chart is divided into six sections ; the top or north one is known as No. 1 section. 

 Starting, we will say, from the north-west buoy, the four boats take up their positions and proceed to 

 take a line of dives as they go east. The north boat steers for the north-east buoy, and the south boat 

 for the intermediate north buoy of the centre line of buoys. The centre intermediate line of buoys are 

 laid as a guide to prevent the boats getting set to leeward. No. 1 boat (No. I coxswain) takes the 

 windward position and No. 2 (No. 2 coxswain) the lee, and these coxswains are responsible for keeping 

 position. Fourteen dives are made from each boat, and as they go across the area six times a total 

 of 336 dives are made over the entire area. An area covers 2 J square miles, and represents a 9-mile 

 course from each boat, although with turning and getting into position for each section the actual distance 

 is 10^ miles. The boats are towed into position or back according to the ship's position. Each boat has 

 a crew of six boatmen with three divers and two linemen, which, together with the coxswain, makes a 

 crew of twelve. The inspection work starts at 7 a.m. , and an area is inspected by 1 p.m. , the inspection 

 occupjring six hours, and each section one. The same area inspected by dredge occupies four hours. 



The smaller charts known as coxswain charts are filled in by each coxswain as each dive is made, 

 and it is from these that the inspection chart is drawn up. 

 57-11 



