to calibrate this speed more accurately than large outboard motors. Trolling plates may be used with larger motors to slow the boat to the desired speed, although some anglers experience mixed results using plates. The downrigger should be set at the depth the target fish are schooling. Different species of fish school at different depths, and those depths also change at different times of year. A fish finder is useful determining this depth. Using a downrigger may be hazardous. Many manmade reservoirs mask submerged trees and other structure beneath the surface. A downrigger's weight may foul on such objects. When such a snag occurs in conjunction with high winds, it may cause a lighter boat to capsize. It is therefore prudent to carry wire cutters to avoid this potentially lethal scenario. Brief history Using a downrigger began in effort to increase productivity of fishing in larger bodies of water. Downriggers are used to troll and maintain the lure's depth in accordance with the thermocline at which the fish species being sought normally feeds. People began using downriggers first in the Great Lakes area. They are now used all over the world to help catch a large variety of fish. In the Great Lakes, downriggers are used to catch a variety of species including chinook salmon, atlantic salmon, lake trout, brown trout and steelhead. Recently discovery of an Edward vom Hofe late 1860s-1870s downrigger found local to Niagara Falls and the Salmon River area point to the reelmaker Edward Vom Hofe Brooklyn New York as the father of the modern downrigger. Prior it was thought that the great lakes Michigan anglers had invented the modern rig. However it was intended for the deep water basin fish listed above and most likely prior to the Hydroelectric plant being built on the Niagara River late 1870s. Somehow the device was lost in time due to the construction of the electric plant most likely causing a disruption in the Salmon fishing. Only one of these examples exist today. Not until the 1950s would a device similar to the Vom Hofe design reappear. It is possible that the modern downrigger introduced in the 1950s was copied from another Vom Hofe made device but for now that can not be proven due to the great time span in between the two designs. Edward vom Hofe was a premier tackle smith and reel maker. There are two