1922] MADRAS PEARL FISHERIES 157 



Each of the circles, of which there are 35 according to my 

 arrangement, is marked with its own distinctive number. The 

 inspection of each circle should be completed in one morning, 

 leaving the afternoon wherein to lift the twelve mark-buoys, shift 

 the inspection vessel, locate the centre of the next circle, and to lay 

 out the buoys for the following day's work. 



Given average fair weather, such an inspection would occupy 

 six weeks. 



If the weather be favourable and other circumstances allow, I 

 recommend that the whole programme be completed in one season, 

 in which case, should the results show no considerable deposit of 

 oysters to be present, the inspection of the following year may be 

 greatly curtailed and be in the nature of traverse prospection 

 rather than detailed circle inspection. Circle inspection and zigzag 

 prospecting may be used in alternate years, but wherever oysters 

 be found in quantity, detailed circle inspection with careful 

 numerical estimates should be carried out annually. Where 

 oysters of over 2% years of age are known to exist, inspection 

 should take place if possible twice a year and a valuation sample 

 drawn at the age of 3^2 years and thereafter at six months' 

 intervals until such time as the valuation amounts to over Rs. TO 

 per 1,000, whereupon it becomes incumbent to consider whether 

 or not a fishery should be held at as early a date as possible. 



Details of the method of circle inspection. — The essential features 

 may be stated as follows : — 



Three flag-buoys are laid out by the attendant launch or tug- 

 boat in the direction of each cardinal point of the compass at 

 distances apart of a quarter of a mile, the inmost buoys taking 

 their distance from the inspection vessel, which is anchored to 

 serve as a pivot mark in the centre of the area to be inspected. 



Four inspection boats (modified whale boats), each manned by 

 a crew of six, together with three divers and two munduks, under 

 the charge of an experienced coxswain, take up equidistant 

 positions between the ship and the first buoy on the north line and 

 row slowly round the ship, retaining their relative positions the 

 while. At regular intervals the crews rest on their oars to allow 

 the divers opportunity to make descents. The result of each dive 

 is reported to the coxswain of the respective boat, who records it 

 upon a diagram with which he is provided. 



