Tangles are especially useful on rocky bottoms where it is impossible 

 to use a dredge or a trawl. They may be used, however, on any type of 

 bottom. Tangles consist of a beam with a few short pieces of chain to 

 which is fastened unravelled rope. 



Dredging Operations. Probably no two persons who have dredged very 

 much agree on just what equipment is best and how it should be used. My 

 father and I have dredged together quite extensively for the past six years 

 and we do not agree on the proper procedure, so no one else will probably 

 agree entirely with me or anyone else. 



The principle of dredging is very simple: you merely throw the dredge 

 overboard, let out about three times as much line as depth, drag it until 

 it is full, pull it up and remove the contents. The only way to learn to 

 dredge is to actually go out and dredge. You will soon be able to tell by 

 the feel of the line if the dredge is on the bottom and digging; in fact, you 

 will soon even be able to tell what type of bottom it is by the way it jerks. 

 Mud hauls usually just get heavier and heavier, sand hauls have many 

 little jerks depending on the character of the sand, while gravel hauls are 

 decidedly jerky and very uneven. The deeper the water, however, the more 

 difficult it is to tell anything about what is happening below. 



It is very important when dredging with cable to keep the line taut 

 by moving the boat forward from the moment the dredge is thrown over- 

 board, otherwise the cable will get full of kinks and break easily. This is 

 2iot so important when using rope, if one is careful to keep the rope clear 

 of the propeller, but it is usually a good idea. 



A weight of some sort should be placed between the line and the 

 dredge to insure that the cutting edge stays on the bottom. A three or four 

 foot piece of heavy log chain is the most convenient kind of weight, but a 

 sash weight, or anything else will do. 



It is impossible to dredge except at very slow speeds; otherwise the 

 dredge is likely to be pulled clear of the bottom. It is much easier to keep 

 the dredge on the bottom when dredging uphill than down; in fact, if the 

 slope is very marked, it is almost impossible to dredge downhill. The 

 more line you have out the easier it is to keep the dredge on the bottom. 



On dredges with iron bridles it is a good idea to make the dredge line 

 fast to one bridle and tie the other to it with a cord. Thus, if the dredge 

 gets caught, the cord will break and the dredge will pull free. As an addi- 

 tional safeguard against breaking the dredge line, it is best to have some 

 arrangement so that the line can slip out of the boat if the dredge gets 

 caught. This is more important with a larger boat. 



If you ever try to dredge on a shallow shale bottom and have difficulty 

 getting anything because you get "hung up" on projecting pieces, try this 

 trick, used successfully at Monterey, California. Use heavy rope, % inch, 

 and when the dredge gets stuck so that you cannot pull it off, open up the 

 motor, slow down, take in about 10 feet of slack, and then speed up again. 

 If it doesn't break off the piece of shale that the dredge is caught on or 



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