Trollers are used primarily on the salmon grounds off southeast Alaska and in the deep-ocean albacore tuna fisheries. They range in size from small skiffs to offshore boats of up to seventy feet. On a troller, the fisherman lowers an array of weighted wire main lines into the ocean from large poles extended from each side of the boat. Several monofilament leaders with baited hooks or lures are attached to each of the main lines as they are lowered. When a fish strikes, a bell on the tip of the pole rings, the fishermen brings in the line, and gaffs the salmon or tuna. Many trollers deliver their fish fresh on ice, but the larger ones have freezers aboard that allow them to make longer trips.