There are several different fisheries off the Pacific Northwest coast, and each uses specialized boats and gear.
Trollers are boats that tow several baited hooks through the water to catch salmon or albacore. They're outfitted with a pair of outriggers, which are kept in an upright position when not fishing, and extended to a 45-degree angle when the lines are out. Salmon trollers, usually 18 to 60 feet, use fish depth, troll speed, and specialized lure to determine species of salmon to be caught. Tuna trollers, usually 38 to 100 feet, can travel hundreds of miles offshore, and stay out for a month or more.
Trawlers are boats that drag funnel-shaped nets through the water to harvest fish or shrimp. Bottom trawlers tow the net along the ocean floor, catching fish that live on or just off the bottom -- rockfish, cod, sablefish, ocean perch, flounder, and sole. Shrimpers tow small-meshed nets just above the ocean floor, using bycatch reduction devices to avoid accidental bycatch of rockfish and halibut. Midwater trawlers fish from just above the bottom to just below the surface, haravesting fish travelling in schools.
Long-liners are boats that drop a very long baited-hook line, which is stretched over the bottom, anchored at each end, and marked by surface buoys, poles, and flags. These boats specialize in halibut or sablefish.
Purse seiners use moveable nets which are used to encircle fish, and are recognizable by the smaller skiff carried on their stern, which is used to pull the net around the schools of fish. Purse seiners specialize in schooling species such as mackerels, sardines, and anchovies.
Gillnetters are smaller vessels, usually 20 to 40 feet, which are used on the Columbia River. The light-weight netting, which hangs in the water, is designed for catching salmon, sturgeon, shad, and smelt. The mesh size is designed to allow steelhead to escape.
Crab boats carry heavy (75-120 pound) crab pots, which are pushed over the side, one at a time, and later hauled in by use of a crab block or gurdy. Crabbing is done seasonally. In off-season, crab pots and their colorful buoys can be seen stacked on docks. During the season, the bright lights of the boats can be seen just offshore.