They haul their lines with electric or hydraulic reels.
(meta data) TITLE: FAO Fisheries & Aquaculture - Fishing vessel type 62 captures 19 Dec 2008 - 03 Jun 2022 About this capture COLLECTED BY Collection: Wikipedia Eventstream The Wayback Machine - https://web.archive.org/web/20190403212959/http://www.fao.org/fishery/vesseltype/360/en FAO Home>Fisheries & AquacultureEspañolFrançaisРусскийFisheries andAquaculture Departmentmore»OK Food and Agriculture Organization of the United Nationsfor a world without hunger Fisheries and Aquaculture Department Home About us ActivitiesStatistics GeoInfo Meetings and NewsPublicationsFact SheetsSource | Citation | XML | Print | PDFSearch These vessels may work day trips or month long voyages. Normally the vessels are powered by engines but the use of sails is also common in trolling operations as the vessel is making way when fishing. In many tropical areas, trolling is conducted by sailing canoes, usually having outriggers for stability. Using a properly designed vessel, trolling can be an economical and efficient way of catching tunas, mackerel and other pelagic fish swimming close to the surface. Vessel ClassLength<30 meters (LOA) PowerallTonnageall (GRT in register tons) Deck ArrangementAccording to area of operation, vessels laid out with wheelhouse and mast in most cases forward. Catch Handling and Processing EquipmentAll. EquipmentDeck EquipmentUndecked canoes may have no equipment or only a hand cranked reel. Purpose built trollers are usually equipped with two or four trolling booms which are raised and lowered by topping lifts and held in fishing position by adjustable stays. Hydraulic or electrically powered reels (gurdies) are frequently used to haul in the lines. Fish Detection EquipmentNo specific fish detection equipment is required for trolling. Visual scouting to detect fish aggregation areas such as floating weed lines is a very common practice. Fishing Gear Trolling lines. Comments/inquiriesSite mapLogine-Bulletin© FAO, 2019powered by FIGIS Logon name: Password:
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Mackerel
Fisheries.

 Chilean jack mackerel are the most commonly fished nonscombroid mackerel, fished as heavily as chub mackerel.  The species has been overfished, and its fishery may now be in danger of collapsing. 
 Smaller mackerel behave like herrings, and are captured in similar ways. Fish species like these, which school near the surface, can be caught efficiently by purse seining. Huge purse-seine vessels use spotter planes to locate the schooling fish. Then they close in using sophisticated sonar to track the shape of the school, which is then encircled with fast auxiliary boats that deploy purse seines as they speed around the school. Suitably designed trollers can also catch mackerels effectively when they swim near the surface. Trollers typically have several long booms which they lift and drop with "topping lifts".