Coho Speed: Why 2.8 Knots Is the Magic Number

Joel Elliott
2026-04-29T14:49:14-07:00

Twenty seasons of GPS data, one stubborn lesson. Here's the trolling speed curve that turns a slow morning into a four-fish limit by 9am.

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Speed Kills

I track my speed every trip. Have for twenty seasons. I have GPS data on something like 2,400 trolling sessions, cross-referenced against catch records, and one lesson keeps showing up in the data over and over again.

For coho salmon, 2.8 knots over ground is the magic number.

Slower than that, and the bite drops off a cliff. Faster, and you're outrunning the strike zone — fish are following but not committing. Right at 2.8, something happens. The bite turns on. Doesn't matter if it's August in the Strait or September off Westport. Coho want 2.8.

Here's the data, the why behind it, and how to dial it in.

The data

Across 2,400-ish trolling sessions where I logged speed and catch:

• Below 2.0 knots: 0.6 coho per hour average

• 2.0 to 2.4 knots: 1.2 coho per hour

• 2.4 to 2.7 knots: 1.9 coho per hour

• 2.7 to 2.9 knots: 2.7 coho per hour ← peak

• 2.9 to 3.2 knots: 1.6 coho per hour

• Above 3.2 knots: 0.8 coho per hour

Notice how steep the curve is on either side. There's almost no penalty for being right at 2.8. There's a huge penalty for being at 2.4 or 3.2. That's a tighter window than most fishermen think.

Why 2.8?

Best guess from the marine biologists I've talked to: it's just below the maximum sustained chase speed of a feeding coho. Coho are visual predators. They see the bait, decide whether they can catch it, and commit. At 2.8 knots, the lure is moving fast enough to look alive but slow enough that the fish thinks 'I can catch that.'

Faster than 3 knots, the fish thinks 'too much work, not gonna catch it.' Slower than 2.4, the lure doesn't trigger the predatory response — looks dead, looks injured, looks suspicious. 2.8 is the sweet spot where it triggers the chase but doesn't outrun the commit.

That's the theory. The data is the data. I trust the data.

How to actually run 2.8 over ground

Speed over ground (SOG) is what your GPS shows. It's what matters to the fish. Speed through water (STW) is what your old paddlewheel transducer shows, and it lies constantly because of current.

If you're running into a 1-knot current, your SOG of 2.8 means your STW is 3.8 — fast enough that the lure is working hard. If you're running with a 1-knot current, your SOG of 2.8 means STW of only 1.8 — lure is barely waking. Same SOG, completely different lure action.

This matters. The fish see the lure based on water speed, not ground speed. So 2.8 SOG is a starting point, not a destination. Watch your rod tips. If the action looks dead, throttle up a quarter knot regardless of what the GPS says. If the lures are over-spinning and the rods are bent down hard, throttle off.

Tackle to match the speed

At 2.8 knots, your gear has to be tuned to that speed:

• Spoons: 3.5 to 4 inch, action-tested at 2.5 to 3 knots. Anything bigger over-rotates.

• Hoochies behind a flasher: 8-10 inch flasher gives the right thump at 2.8.

• Plug-cut herring: cut for a tight rotation at 2.5-3 knots, about 4 seconds per turn.

If you're running gear designed for 1.8 knots (slower) at 2.8, it spins out and looks unnatural. If you're running gear designed for 3.5 knots (faster) at 2.8, it barely waggles. Match the gear to the speed.

2.8 SOG is the starting point. Watch your rod tips. They'll tell you when to adjust.

When 2.8 doesn't work

Couple exceptions worth knowing:

Cold water (under 50°F): bump it down to 2.4-2.6. Coho metabolism slows in cold water and they won't chase as hard.

Heavy current with bait stacked on a tide line: stay at 2.8 SOG, but reposition to keep the lures in the strike zone longer. Multiple slow passes beats one fast pass through a hot spot.

Pressured fish (lots of boats): bump it up to 3.0-3.2. Pressured coho see hundreds of lures a day, and the thing moving slightly faster sometimes triggers the strike when nothing else will.

Watch the rod tips

All of this is a starting framework. The real test is the rod tip. A coho-correct lure speed gives you a rod tip that ticks rhythmically, like a quiet metronome. If the tip is dead-still, you're too slow. If it's bent down hard, you're too fast. Adjust the throttle by a quarter knot at a time and watch.

And when you find the bite, write down your speed. Track it for a season. You'll start to see the same number coming up over and over. For me, that number's been 2.8 for twenty years.