Setting Up a Dredge Pulley for Billfish

Dredge Pulley Setup

A dredge pulley setup takes the pull of a heavy dredge off the rod and the transom and moves it up to the outrigger, where a block-and-tackle splits the load. The line runs from the dredge reel up to a pulley at the outrigger's first spreader, down around a second pulley at the front of the dredge, and back up to the outrigger. That triangle of line puts the pulling point high and outboard, keeps the dredge swimming in clean water off the corner instead of tumbling in the prop wash, and leaves the reel pulling about half the load.

The system described here is the one Capt. Glenn Cameron and RJ Boyle rig and fish in our dredge fishing video library. Glenn runs out of Fort Pierce, and RJ calls him the man behind much of modern dredge fishing; RJ breaks down the rig and the reel that pulls it. Where this article goes past what anyone else has published, it is because we did the math on the rig ourselves, and we show it.

How Does a Dredge Pulley System Work?

The Three Pulleys and What Each One Does

RJ calls the pulley system "by far, the most difficult for most people to understand," and admits it took him a while to grasp. Here is what each piece does:

• The outrigger pulley takes more load than anything else in the system, so it gets the best block on the boat. RJ runs a Harken at the first spreader and calls it "a must."
• The dredge pulley rides at the front of the dredge on the reel line. Because the line passes around it and back up to the outrigger, it is the piece that splits the load.
• The lazy line pulley rides on the outside leg of the dredge line on a light rope tied off in the cockpit, and it is the piece most rigs leave out.

When the reel takes in line, the dredge pulley climbs toward the outrigger and brings the dredge with it.

Why the Lazy Line Matters

The lazy line solves a problem you only meet in a turn. When a fish is hooked and the boat swings toward it, the dredge on that side can slide farther away from the boat just as you are trying to bring it in. With a pulley on the lazy line riding the dredge line, a crewman can pull the dredge toward the boat by hand while the reel works. Where it ties off and how it is rigged depend on the boat, and RJ walks through his on camera.

Why the Load Is Cut in Half, and When It Isn't

The dredge pulley hangs on two legs of line, one from the reel side and one from the anchor, so each carries roughly half the dredge's pull. That is a two-to-one mechanical advantage, and RJ's reason for it is simple: "There's so much drag that's put and pull that's on the dredge that basically you're using this block and tackle system to cut down on the pressure, the pressure on the rod, the pressure at the outrigger."

What nobody writing about dredges tells you is that the two-to-one only holds when the two legs run close to parallel. The tension in each leg equals the dredge's pull divided by twice the cosine of half the angle between the legs. With F as the dredge's pull:

• Legs parallel: each leg, and the reel, carries 0.50 F
• Legs 60 degrees apart: 0.58 F
• Legs 90 degrees apart: 0.71 F
• Legs 120 degrees apart: 1.0 F, and the pulleys do nothing for the reel

With the dredge well back and the pulley and anchor a few feet apart on the outrigger, the legs are nearly parallel and you get almost the full advantage. The geometry turns against you when the dredge runs short and the two outrigger points are spread far apart, which is exactly the situation on a small boat with a short boom. A long, narrow triangle of line is what earns the two-to-one.

Direct Pull vs. Block-and-Tackle (A-Frame)

The rig above is what most crews mean by an A-frame: the name describes the triangle the line makes, not a physical frame. The alternative is a direct pull, where the line runs through one pulley on the outrigger and straight down to the dredge.

Our own course crew disagrees on this, and the disagreement is the lesson. One of the mates fished a single pulley in Mexico and says "it worked great." RJ's answer is that the boat was trolling about six and a half knots there, while double and triple dredges at marlin speeds are a different load, and his advice to anyone starting out is "stick with the triple pulley." Some top crews have gone direct. Ken Cofer of Tranquilo told Marlin Magazine that "these reels are so powerful that we no longer need to use a pulley system," and his crew reinforced the outrigger to take it. Capt. Anthony Pino kept his A-frame after upgrading reels because "the A-frame avoids a single stress point."

What the Outrigger Actually Carries

Tranquilo's reinforcement makes sense once you work out the load. A pulley with line running in and out of it is pulled by both legs at once, with a force equal to twice the line tension times the cosine of half the angle between them. On a direct pull, both legs carry the dredge's full pull. With the reel leg and the dredge leg 60 degrees apart, the single outrigger pulley takes about 1.7 times the dredge's pull; at 90 degrees, about 1.4 times. One point on the outrigger carries more than the dredge itself pulls.

On the A-frame, each leg carries about half, so the outrigger pulley sees roughly half to nine-tenths of the dredge's pull and the anchor takes about half. The load is spread across two points instead of one, which is the physics behind Pino's comment.

Retrieval Time, Worked Out

What does the A-frame cost in speed? Using the makers' published top speeds, with no load on the line:

Real times run longer, because a loaded reel slows down. At 50 feet back the A-frame costs a few seconds on a fast reel. At 100 feet back on a 12-volt reel, it can be the difference between the dredge clearing while the fish is still in the spread and the dredge still coming when the fish turns toward it.

The choice comes down to load against speed, and trolling speed decides more than anything else. A strong, fast reel, a reinforced outrigger, a single dredge, and sailfish speeds point to a direct pull. Double or triple dredges, speeds of seven and a half knots and up, a smaller reel, or an outrigger you would rather not load at one point all point to the A-frame.

Dredge Pulley Hardware

Choosing the Pulleys

Put your best block at the outrigger, where the load concentrates. The pulleys at the dredge and on the lazy line see less load, and RJ uses Ronstan singles there, but every pulley in the system still needs smooth bearings and corrosion resistance. Plastic-frame pulleys are a common recommendation, since twisting line can chafe against a metal frame.

Braided line can wedge between the wheel and the side plates of an ordinary pulley and fray. Rupp Marine's braid-proof outrigger dredge pulley, built on a 40mm Harken titanium sheave with no pinch points between the wheel and the plates, is designed around that problem. Larger aluminum pulleys, such as the 4-inch and 6-inch Precision Dredge Pulley that Rupp sells, turn their bearings at a lower RPM for the same line speed and are easier on braid.

The Dredge Lead

The pulley system ends at the dredge lead, which holds the dredge down. Glenn runs anywhere from two to eight pounds in front of the dredge, "depending on your boat and your speed." The rigging matters as much as the weight. RJ keeps a second set of leads rigged specifically for running down sea, where the boat's pitch can snap the line tight, lift the lead out of the water, and pull the dredge arms through the surface. How those leads differ is one of the details he shows in the course.

Mounting and Reinforcement

Mount the outrigger pulley where the line has a clean, straight run from the reel and the outrigger can take the load. RJ notes this is the one part of the rig that changes from boat to boat, because spreader positions differ. Keep it at the first spreader or as low as practical, so the dredge line stays clear of the anglers' lines in a turn. Check your outrigger maker's load guidance, make the anchor as solid as the pulley mount, and on a boom or a light outrigger, add a safety line to a forward cleat.

Electric Reels for Pulling Dredges

Lindgren-Pitman and KOBO

RJ is blunt: in his view the Lindgren-Pitman S1200 is "the only reel to use for dredge fishing," because few reels can pull double dredges at six to eight knots fast enough to get them away from a fish crashing the dredge. He also says Lindgren-Pitman has supported him and that his tackle business sells the competition, so weigh it with that in mind. Lindgren-Pitman's current 12-volt reels are the S2-1200 and SV-1200, and the 24-volt SV-2400 is rated at more than 150 pounds of pull, with 24 volts cutting the loss from voltage drop on larger boats.

KOBO's Power Reel runs on 12 or 24 volts and is built for dredges as well as deep dropping and swordfishing. For dredges, pull matters more than drag: KOBO lists about 60 pounds of pull at 12 volts and 90 at 24 volts, against the SV-2400's 150-plus. On a pulley rig the reel only pulls about half the dredge's load, which is where a reel with less pull earns its place.

Why You Should Not Fill the Dredge Spool

RJ suggests leaving your dredge spool well short of full on purpose: "the more you fill this spool, the more torque you're putting on the reel." The physics backs him up. An electric motor produces a set torque, and the pull at the line equals that torque divided by the radius the line comes off. A spool filled to the top has a larger working radius, so the same motor pulls less and works harder against the same dredge. Spooling heavy line onto a dredge reel is its own job, and RJ shows how in our course on filling a dredge spool by yourself.

The Drag Is the Fuse

RJ sets his drag preset high enough to pull the dredge in, and never locks it. "If something happens, if it gets fouled up, fish is pulling on it, you don't want everything to come down pulling on the rigger." That is the right way to think about it: the drag is the weak link you choose, set to slip before the outrigger or the pulley mount does. Where he sets it, and how he checks it without a scale, is in the course.

The Counter Is Not Distance

The S1200 counts spool rotations, and the number on the display is line off the spool, not distance behind the boat. The pulley rig is why they differ. On an A-frame, every foot of setback uses about two feet of line, so a counter reading that puts the dredge 100 feet back on a direct pull puts it roughly half that distance on an A-frame. Know which you are running before you copy anyone's number. Set the auto-stop where you want the dredge to finish, and the reel brings it to that point every time while the crew works the fish.

How Far Back and How Deep Should a Dredge Run?

There is no single answer, and Glenn is clear about why: "every single boat you fish is different. Your clear spots behind your boat are different." His rule is to fish the dredge "back far enough where it stays underwater well, without having to add too much lead," so it never skips or jumps, and then build the spread around it. In his words, a dredge set right should "physically pulsate when you're dragging it through the water."

Speed sets the limit on the dredge itself. RJ fishes light wire dredges for sailfish at four to six knots at most, and heavy-duty dredges up to about eight knots, where the arms start to fold. Glenn trolls his general billfish spread at seven to seven and a half knots on a calm day, faster when he is targeting blue and white marlin.

Small Boat and Center Console Options

On boats without big outriggers, RJ pulls the dredge directly off the rod tip, keeps the spool short of full, and expects to retrieve on low speed. Marlin Magazine notes crews cleating a dredge off at the transom or running it from a downrigger. Only the cleat-off rig gives up load-sharing entirely; a downrigger or dredge boom can still run a pulley triangle with a safety line to a cleat. Remember the angle problem: on a short boom with the dredge close behind, the triangle is wide and the advantage shrinks. Sport Fishing puts small-boat dredges from just under the surface to about 6 feet deep, 20 to 30 feet back.

Working the Dredge When a Fish Shows

When a billfish comes up on the dredge, the crew has squid chains and rods to clear at the same moment, which is why RJ wants a reel he can switch on and walk away from instead of nursing it in by hand. When Glenn hooks a fish, he clears his inside teasers and goes into a hard turn toward it. That turn is when the dredge on the inside swings away from the boat, and when the lazy line earns its place. For how dredges fit into a sailfish spread and the bait-and-switch that follows, see our article on dredge fishing with Bill Pino of Squidnation.

Inspection and Maintenance

Before every trip, inspect the pulleys, swivels, crimps, and line, and look for chafe where the line runs through the pulleys and where the lazy line rides. Flush the pulleys with fresh water and do not grease them; Harken says grease makes bearings skid instead of roll. Replace on condition: a sheave that binds or wobbles, a cracked side plate, a swivel that does not spin freely, or line with chafe or flat spots comes off the boat. Carry a backup dredge, since wahoo, mahi, and barracuda will eat dredge baits.

Dredge Fishing Questions

Getting the Most From a Dredge Pulley

A dredge pulley rig does two jobs: it moves the pulling point high and outboard so the dredge swims in clean water, and it takes load off the reel, the rod holder, and the transom. The details are what make it work: the outrigger pulley low and out from the poles, a long and narrow triangle, a lazy line for the turns, a spool left short, and a drag set to slip before the outrigger does. Then let your speed and your dredges decide whether you want the load split or the speed back.

What this article cannot give you is the rig going together in someone's hands. RJ and Glenn build every piece of it on camera, from the pulley layout to the leads and the dredges themselves, and then fish it, in our Dredge Fishing for Billfish course.

Seth Horne Founder and CEO