The trolling rig

What it's for

Deep, cold-water fish that roam open water: lake trout, Arctic char, landlocked and Pacific salmon, and walleye. These fish hold at a depth that changes with the season and the water temperature, often well down in the water, and they cover ground, so you cover ground too by towing a lure past them. The whole art of trolling is putting the lure at the right depth and speed and keeping it there. That is why most of this page is about the three ways to get a lure down, because once it is at the fish, the lure and the terminal end are simple.

The rig at a glance

Whichever method gets the lure down, the business end is the same idea: a leader to the lure, often behind an attractor. Run a mono or fluorocarbon leader, then the lure, a spoon, a plug or a flasher-and-fly or dodger-and-bait set-up that fish for lake trout, char and salmon take well. For walleye, a worm harness or a small crankbait behind leadcore is the staple. Tie the leader to the main line, the leadcore or the downrigger line with a Palomar knot, and tie a mono leader to the lure with an improved clinch knot. Use a snap swivel ahead of a spoon or spinner so it can turn freely without twisting the line.

Downrigger, leadcore or flatline

This is the choice that decides everything. All three tow a lure behind the boat; they differ in how they get it to depth and how much control you have. Here is each in plain terms.

Downrigger. A separate heavy ball (commonly 3 to 5 kg / 6 to 12 lb) hangs on its own steel cable from a small winch on the boat, lowered to a depth you read off a counter. Your fishing line clips into a release near the ball, so the lure trails behind at that exact depth on a normal mono or braid line. When a fish hits, the line pops free of the clip and you fight it on a clean line with no extra weight. The strength of the downrigger is precise, repeatable depth and a direct fight, which is why it is the standard for deep lake trout, char and salmon.

Leadcore. A line with a heavy lead core inside a braided sheath, sold in colour-coded segments (each colour is about 9 m / 10 yards). It sinks as you let it out, so the more colours you run, the deeper the lure goes, roughly a few metres per colour at trolling speed. You tie a mono or fluorocarbon leader to the end and the lure to that. Leadcore needs no extra gear and you feel the fish directly through the rod, which makes it the simplest way to fish a set depth, popular for walleye and for trout and salmon in the middle depths.

Flatline. The simplest of all: the line runs straight off the rod behind the boat with no downrigger and no lead line, and the depth comes from the lure itself, a diving plug that dives as you let out line, or a lure with a little added weight. Flatlining works when the fish are shallow, in the top few metres, which is common in spring and early morning when cold-water fish are near the surface and along the shore.

Downrigger – a weighted ball on a separate cable, line clips to a release. Deep and precise (down to 30 m and more). Exact, repeatable depth; a clean fight after the line releases.

Leadcore – a lead-cored line sinks as you let out colours. Shallow to mid (roughly a few metres per colour). Direct feel through the rod; depth set by colours out.

Flatline – a diving or weighted lure straight off the rod. Shallow (the top few metres). The simplest; depth set by the lure and the line out.

How to build it

1. Set up the depth method. Choose by how deep the fish are. For a downrigger, lower the ball to the depth on the counter and clip your fishing line into a release near it. For leadcore, let out the number of colours that reaches the depth you want. For a flatline, let a diving or weighted lure out behind the boat. This step is the rig: it is what puts the lure at the fish.
2. Join the leader. Tie a mono or fluorocarbon leader, 2 to 6 m long, to the end of the leadcore, the downrigger line or the flatline with a Palomar knot onto a small swivel, which keeps the leader and the line separate and stops twist. The leader gives the lure room to work behind the heavier line.
3. Tie on the lure. Tie the lure to the end of the mono or fluorocarbon leader. On mono, an improved clinch knot is the simple, reliable tie to a spoon, plug or harness. Add a snap swivel ahead of a spoon or spinner so it turns freely without twisting the leader.

How to fish it

Find the depth the fish are holding first, with a sounder or local advice, then choose the method that reaches it: a downrigger for deep fish, leadcore for the middle depths, a flatline when they are near the surface. Set the lure at that depth, set a steady trolling speed to suit the lure (slower for spoons and flasher set-ups, a touch faster for plugs), and watch the rod tips. On a downrigger the rod sits bent over in the holder and springs straight when the line pops free of the clip, which is the take. On leadcore or a flatline the rod loads up and you feel the fish directly. Vary the depth and speed until you get a hit, then troll the same line again. In spring and early morning the fish are often shallow, so start with a flatline; through summer they go deep and the downrigger or more colours of leadcore reaches them.

Where this rig works

Trolling is the way to fish open, deep, cold water across the atlas. In Europe it takes lake trout and Arctic char on Lake Vänern in Sweden, Lake Geneva on the Swiss and French line, and Lake Maggiore in Italy. In North America it is the method for lake trout and salmon on Lake Simcoe and the Bay of Quinte in Ontario, and for walleye on Lake Erie; for Pacific salmon on the Kenai and Campbell rivers and their estuaries; and in Australia for trout on Lake Eildon. As the atlas grows, every new water that uses a trolling rig will link to this same page.

Trolling rig questions