MANUFACTURE OF LEATHER FROM MARINE SOURCES 



541 



8 inches in diameter, any ordinary fish will pass through. Since the sharks fol- 

 lowing in the wake of the fish are so much larger, they become entangled in the 

 meshes and are so retained. The catch of course varies with fisherman's luck, and 

 may be from nil to any number. Three men comprise the crew of a fishing boat, 



600' to 1800' 



...Steel float 



Ocean 



-" J Rope or g coble 



Surface 



Fig. 25—1. Different types of gear used in the shark fishing industry. 



and the best boat for the purpose is the Seabright dory. In hauling the net one 

 end is gathered up and the boat pulled alongside; the shark is then brought to 

 the surface, and with a sharp blow on the head is rendered harmless. A hook 

 is then placed in the mouth and the shark is pulled aboard by means of a small 

 derrick. 



Considerable success has been experienced in catching sharks by means of set 

 lines. These lines are made up of ground lines composed of sections of %6-inch 

 galvanized chain, 600 to 1,000 feet in length. At 30-foot intervals a 6-foot length 

 of the chain, fitted with swivel harness snaps and a large shark hook is attached. 

 The line is anchored at both ends and marked with flag buoys. One boat with 

 4 men can tend 1,200 to 1,800 feet of line per day. 



