Trolling is a method of fishing where one or more fishing lines, baited with lures or bait fish, are drawn through the water. This may be behind a moving boat, or by slowly winding the line in when fishing from a static position, or even sweeping the line from side-to-side, e.g. when fishing from a jetty. Trolling is used to catch pelagic fish such as salmon, mackerel and kingfish. In American English, trolling can be phonetically confused with trawling, a different method of fishing where a net (trawl) is drawn through the water instead of lines. Trolling is used both for recreational and commercial fishing whereas trawling is used mainly for commercial fishing. Trolling from a moving boat involves moving quite slowly through the water. This can be accomplished with the use of a special trolling motor. Multiple lines are often used, and outriggers can be used to spread the lines more widely and reduce their chances of tangling. Downriggers can also be used to keep the lures or baits trailing at a desired depth. Line-spreading trolling devices Outriggers Outriggers are poles which allow a boat to troll several lines in the water without tangling. A boat which trolls enough lines can simulate a school of fish. Downrigger Downrigger are devices used while trolling to keep a bait or lure at the desired depth. In practice, fish swim at different depths according to factors such as the temperature and amount of light in the water, and the speed and direction of water currents. A downrigger consists of a one or two metre horizontal pole which supports a weight, typically about three kilograms of lead, on a steel cable. A clip called a "line release" attaches the fishing line to the weight, and the bait or lure is attached to the release. The fishing line is reeled in by a spool powered either by manual cranking or by an electric motor. Using a downrigger can be hazardous. For example, man-made reservoirs can contain submerged trees and other structures beneath the surface which downriggers can snag. Paravanes "Paravanes" (underwater kites) are sometimes used as depth controlling devices, particularly in commercial tuna fishing operations. These kites have various shapes, such as arrowhead paravanes, flexi-wing paravanes, and bi-wing paravanes. The devices can place the lure or bait at designated depths and positions; and in this way multiple devices can be towed at the same