You may be using line between 10 to 40 pound test depending on the situation. Some anglers go as light as 10 pound line when casting for lake trout in the shallows in the spring and when jig fishing on clear water lakes. Most anglers will be using somewhere between 20 to 30 pound test line if they are on a lake that has some big fish in it. When trolling, you may even go heavier to avoid losing fish and snapping lines on a big fish.