A Primer on Lead-Core Trolling Line

Easier to Use Than Wire Line, Popular for Mid-Depth Salmon and Trout Fishing


Weighted lines are core-heavy products that sink and are used for deep trolling. The objective in using a weighted line is to bring a lure or bait to depths that cannot be reached by flatline trolling, and where other devices are unavailable. Lead core is the foremost type of weighted line, but similar products have a flexible non-toxic lead substitute.

These are not conventional fishing lines to which some external weight has been added in order to get a lure or bait deep.

Instead, they feature a pliable, dense core (usually lead) that is covered by a sheath of another material, perhaps braided nylon, Dacron, or braided microfilament. They are available in a somewhat limited range of strengths, roughly from 12- to 60-pound-test, mostly from the upper 20s on up, and in 100- and 200-yard spools. To learn what the actual breaking strengths are you’d have to contact the manufacturer, although you can compare products based on their diameter. Lead-core line is color-coded every 10 yards, and users refer to 100 yards as being a “full core,” or ten colors, and a “half core” as being 50 yards, or five colors.

Good Sinking Ability, Simple to Use

Lead-core lines have the density to sink on their own without the addition of external objects, although the bulky diameter of the line offsets some of the sinking ability at trolling speed, usually meaning that to get very deep, great lengths have to be trolled or the boat moved very slowly.

In saltwater, and in some freshwater applications, trollers who desire to get lures deep prefer wire line; many freshwater anglers will use copper line as an alternative to wire or lead-core lines, as copper sinks faster and thus deeper, requiring less line to reach a specific depth.

Lead-core lines are not as useful at high speeds and where there is current but are easier to use than wire or copper.

They rarely create kinking or jamming problems (except when the sheath breaks), and can easily be wound on a reel and set out when a boat is moving forward. They cannot be cast. Being color-coded aids in determining how much is out, although this won’t necessarily tell you how deep the lure is, as this varies with the makeup of the particular lead-core line. The manufacturer may indicate how deep the line will take a lure at a particular speed and with a certain length (or number of colors) employed. In general, this varies from 2 to 5 feet per color.

Lead-core lines are available in coated and uncoated versions, the former using some type of plastic. The coating may help resist abrasion, but generally, these lines are not very abrasion resistant. They have less stretch than some similar-strength nylon monofilaments, but they do stretch. They will corrode in saltwater, and have to be taken off the reel spool and rinsed, in part explaining why wire line is universally preferred in saltwater. 

One manufacturer, Sufix, has a product with a microfilament sheath, which is said to offer greater sensitivity and decreased stretch, and can be used with smaller reels; coupled with a dense core, this line requires less of it to be deployed in order to reach the same depth as a traditional lead-core line.

A comparable product is offered by Tuf.

Rods, Reels, and Leaders

Tackle to be used with lead-core lines includes a relatively stout rod from 8 to 9 feet long, and conventional reels large enough to hold this bulky product plus backing. Levelwind conventional reels can be used while spinning reels are not suitable. The more lead-core line that you put on a reel, the larger the spool needs to be. Using a thin diameter braided microfilament line as backing helps with reel size and capacity. A long monofilament or fluorocarbon leader (at least 15 feet) is tied to the business end of the lead-core line, and a lure is attached to that. Albright knots are used to connect leader or backing to the lead-core line.

Limits the Fight of the Fish

Trolling with lead-core line was once a principal means of fishing deep in freshwater, but decreased greatly in popularity with the increased usage of downriggers and diving planers.

It has enjoyed some resurgence among lake trout, salmon, and walleye trollers, and may be effective when other trolling tools are not.

To many anglers, lead-core line trolling is not as satisfying as using lighter and more challenging tackle. The problem is that lead-core lines make fish-landing mostly a reel-cranking, winch-the-fish-up affair. If you catch a giant, it will surely fight well enough for you to know it's there. But for every giant you hook, you'll catch a lot of small- to medium-size fish, which don't give as good an account of themselves on this weighted line as they do on finer line because they must resist the bulky drag of the line in the water.