Trolling is the dominant technique for Great Lakes salmon — and it’s deceptively complex. A bare-bones definition is “pulling lures behind a moving boat,” but the actual practice involves a half-dozen variables that all matter: trolling speed, depth control, lure presentation, spread layout, electronics interpretation, and reaction to changing conditions. Get any one of these wrong and your catch rate drops dramatically. Get them all right and you’ll have days that feel like the fish are jumping into the boat.
This guide ties together everything else in the Great Lakes salmon section — the downriggers, planer boards, spoons, coho lures, and reels — into a single technique system. Read this once, then keep it bookmarked as a reference for setting up your trolling pattern at the start of each trip.
Trolling Speed by Species
Trolling speed is the single most important variable you control. The right speed activates the lure action; the wrong speed kills it. Different species respond to different speed ranges.
| Target Species | Optimal Speed (GPS) | Lure Action at Speed |
|---|---|---|
| King Salmon | 2.4–2.6 mph | Wider wobble, more flash |
| Coho Salmon | 2.5–3.0 mph | Tighter, more frequent wobble |
| Atlantic Salmon | 2.4–2.8 mph | Moderate, varies by spoon |
| Lake Trout | 1.5–2.2 mph | Slower, more deliberate |
| Steelhead | 2.5–3.0 mph | Fast, aggressive action |
| Mixed Spread | 2.4–2.7 mph | Compromise that hits all species |
GPS speed is what matters, not the boat’s speedometer. Currents on the Great Lakes can mean a boat doing 2.5 mph through the water is actually moving 1.8 or 3.0 mph relative to ground depending on direction. Your GPS speed over ground is what controls lure presentation. Always go by GPS.
Understanding the Thermocline
The thermocline is where salmon live in summer. It’s the layer in the water column where temperature drops rapidly with depth — typically a 20-degree drop over 20 feet. By July, a typical Lake Michigan profile is:
- Surface to 40 ft: 65–72°F — too warm for most salmonids
- 40–60 ft: Rapid thermocline transition
- 60–120 ft: 48–58°F — the salmon zone
- Below 120 ft: 42–48°F — lake trout territory
Your downrigger depth needs to put your spread in the salmon zone. A temp/speed probe at downrigger depth gives you exact readings; without one, you estimate from surface temp and depth charts. See the king salmon temperature guide and coho temperature guide for species-specific depths.
Building Your Trolling Spread
A trolling spread is the arrangement of multiple lines running off the boat at different depths and horizontal positions. The goal is to maximize coverage without lines tangling. A typical Great Lakes salmon spread:
The Six-Rod Recreational Spread
This is what most serious recreational anglers run on a typical fishing day:
- Downrigger #1 (port) — At thermocline depth (e.g., 80 feet), 50 feet behind the boat
- Downrigger #2 (starboard) — At thermocline depth, 50 feet behind the boat (mirror)
- Dipsy diver #1 (port wide) — Set to 100–120 feet out, depth 40–60 feet
- Dipsy diver #2 (starboard wide) — Mirror of #3
- Lead core or copper #1 (back of boat) — Mid-depth, 30–50 feet down
- Center back rod — Direct line behind the boat, surface or very shallow
This spread covers a horizontal width of about 200 feet behind the boat at depths from surface to thermocline. Six different depth/horizontal combinations dramatically increase the odds of intercepting fish.
The Eight-Rod Charter Spread
Charter boats add two more rods, usually:
- Planer board (port outside) — 100–150 feet from boat, surface to shallow depth
- Planer board (starboard outside) — Mirror
The result is 250 feet of horizontal coverage at the back of the boat. Charter captains can manage this much spread because they have a deckhand and years of experience reading multiple rods simultaneously.
Depth Control: Putting Lures in the Zone
Three primary methods get lures to the right depth:
Downriggers — The most precise method. The weight pulls cable down to a specific depth (read off the digital counter), and the fishing line clips to the cable at that depth. When a fish hits, the line releases from the cable and fights free. See the downrigger guide for setup.
Lead core or copper line — The line itself sinks. Lead core is typically marked in 10-yard color segments, with each segment going down about 5 feet at trolling speed. Copper line sinks faster. The downside is the line is heavy and reduces your sense of strikes; the upside is no downrigger equipment is needed. Sufix Lead Core is the standard.
Dipsy divers — Diving planers that pull a fishing line down and sideways. Set on a numbered dial system (most use 0–3 settings), they reach 30–80 feet down depending on setting and line out. Excellent for spreading lines wider than the boat without downriggers.
A complete spread uses all three methods to cover different depths and positions.
Reading Your Electronics
Modern fish finders show the thermocline as a distinct band of color or density change in the water column. Below the thermocline, you’ll often see arches (individual fish) or balls (bait schools) in the cold water. Reading the screen tells you exactly where to set your spread:
- Thermocline depth shows as a horizontal band of color change, usually 30–60 feet below surface in summer
- Bait balls appear as dense scattered marks, often suspended above or near the thermocline
- Individual fish arches below or in the thermocline are your targets — set the spread at their depth
- Bottom contour matters even at depth — look for fish near structure rather than open water
A temp/speed probe at downrigger depth combines surface electronics with at-depth confirmation. Most charter captains run probes; serious recreational anglers should too if they fish more than 20 days a year.
Setting the Spread: A Sequence
Here’s the order most charter captains use when starting a trolling pass:
- Identify the target depth. Check electronics for thermocline, bait, fish marks. Decide where to set your primary depth.
- Get the boat to trolling speed. 2.4–2.7 mph GPS. Run for a minute to stabilize.
- Set the downriggers first. Drop the weight to target depth. Clip the line in at the rigger. Set the rod in the holder with appropriate drag.
- Set the dipsy divers next. Drop the diver behind the boat, let line out to reach target depth, set the rod.
- Add lead core / copper. Let out the segment count needed for your target depth. Set the rod.
- Set planer boards last (if running them). Lure first, then clip into the board release, then let the board plane out.
- Watch for strikes. First 5 minutes after setting often produce the first hits as lures find baseline running depth and action.
Reacting to Strikes
The moment of truth. What you do in the 10 seconds after a hit determines whether the fish makes it to the net:
Don’t slow the boat. Keep trolling at speed while the fish is being fought. Slowing the boat puts slack in the line and changes the angle of fight. The boat stays at speed until the fish is at the net.
Bring the rod to vertical. The angler picks up the rod with the bend already loaded with the fight, then brings it to vertical to set the hook fully.
Maintain steady pressure. Don’t pump and reel like saltwater fighting — Great Lakes salmon need consistent pressure that wears them down. The drag should be set to give line on hard runs and hold otherwise.
Reel other lines in if needed. If the fight is going to cross other rods (likely on dipsy and downrigger setups), reel in the rods the fish might cross before fully fighting it.
Net the fish smoothly. A big net handled smoothly under the fish brings it aboard. Don’t lift with the line — the leader can break under the lift weight, losing the fish at the boat.
Reading the Day: When to Change Up
Some days the spread you set at 6 AM produces all day. Most days it doesn’t. Knowing when to adjust:
If you haven’t had a strike in 30 minutes — Change something. Spoon color, depth, speed, or location.
If only one rod is producing — Mimic that rod across the spread. If the wide dipsy at 60 feet down is hitting, set another rod at similar depth.
If you’re getting follows but no hookups — Slow the trolling speed slightly. Following fish that don’t commit often need a slightly slower presentation.
If the bite turns off suddenly — Often a temperature shift or bait movement. Check electronics for new thermocline depth or bait location. Reset spread accordingly.
If marks are showing but no strikes — Fish are present but inactive. Change spoon color (try Glo or UV), add a flasher, or wait for a feeding window (often dawn/dusk).
Common Trolling Mistakes
Trolling too fast for kings. 2.4–2.6 mph is the king range. Most anglers troll too fast (2.8–3.0+) and miss kings that won’t chase that quickly. Slow down and the kings will eat.
Not enough variety in the spread. Running the same color/size lure on every rod kills your information feedback. Mix it up so when one rod produces you know what pattern is working.
Setting the spread once and leaving it. The fish move during the day. Adjust depth and lure choice every 30–60 minutes based on what’s producing and what electronics show.
Skipping the speed verification. Don’t trust the boat speedometer. Use GPS speed over ground.
Running lines too close together. Tangled spreads cost time and lost fish. Plan your line spacing carefully and pay attention as you set rods.
Ignoring barometric pressure. Falling barometer triggers feeding. Rising or stable high pressure usually slows the bite. Build trip planning around pressure trends, not just calendar days.
Gear Required for Trolling
- Best Downriggers — depth control system
- Best Planer Boards — horizontal coverage
- Best Salmon Trolling Rods — purpose-built for the application
- Best Salmon Trolling Reels — line counters for depth precision
- Best King Salmon Spoons — the primary lures
- Best Coho Salmon Lures — cut plugs, body baits, spinners
- Sufix Lead Core Line — segmented depth line
- Dodger Assortment — attractors ahead of cut plugs
- Pro-Troll ProChip 11 Flasher — primary attractor
Frequently Asked Questions
What’s the best trolling speed for salmon?
2.4–2.6 mph for kings. 2.5–3.0 mph for coho. 1.5–2.2 mph for lake trout. A mixed-species spread typically runs 2.4–2.7 mph as a compromise. GPS speed over ground matters, not boat speedometer.
How deep should I troll for salmon?
Depends on season and thermocline. Spring: 15–35 feet. Early summer: 30–60 feet. Peak summer: 60–120 feet. Pre-spawn fall: 40–80 feet. Always target the prime temperature band (52–56°F for kings, 55–58°F for coho).
What’s the right trolling spread for salmon?
Six rods is the standard recreational spread: 2 downriggers, 2 dipsy divers, 1 lead core/copper, 1 back rod. Add planer boards to expand to 8 rods for serious fishing. Match the spread to your boat size, crew, and electronic capacity.
How do I find salmon while trolling?
Read your electronics. Thermocline depth, bait balls, and fish arches all show. Set the spread at the depth where bait and fish are appearing. Use the SST charts and chlorophyll maps to plan locations before launching.
Should I use braid or mono for salmon trolling?
30lb PowerPro braid as mainline with a 25–30 foot mono top shot is the most common setup. Braid gives depth precision; mono gives strike absorption near the lure. Pure mono works but loses the depth precision.
What time of day is best for salmon trolling?
Dawn and dusk produce the most aggressive feeding. Mid-morning to early afternoon can be tough on bright days. Late afternoon often produces a second feeding window. Plan trips to be on the water for both light windows when possible.
Plan Your Trip
- SST Charts — find temperature breaks before launching
- Chlorophyll Maps — locate bait-holding water
- Fleet Tracker — see where charters are running
- Marine Weather — barometer matters for feeding activity
- AI Fishing Predictions — daily forecasts
- Lake Michigan Fishing Season Calendar
- Great Lakes Fishing Trips
Related Guides
- Best Water Temp for King Salmon
- Best Water Temp for Coho Salmon
- Best Water Temp for Atlantic Salmon
- Best Water Temp for Lake Trout
- Best King Salmon Spoons
- Best Coho Salmon Lures
- Best Downriggers
- Best Planer Boards
- Best Salmon Trolling Rods
- Best Salmon Trolling Reels
- Lake Michigan Fishing Season Calendar
- Lake Ontario Salmon Fishing
- Manistee River Salmon Fishing
- Pier Fishing for Salmon
- River Salmon Fishing Guide
- How to Read SST Charts
- Finding Temperature Breaks
- Great Lakes Fishing Trips
Tight lines!








