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This week's Feature Blog

Getting Creative With Fishing Line Types and Diameter

By: Mark Romanack

The Precision Trolling Data app incorporates on the water testing to confirm the diving depth of popular lures and trolling devices based on different line diameters, line types and trolling leads. This painstakingly slow process is the only way to confirm the data created is as accurate as humanly possible.

​ Fishing line types and also line diameters play a critical roll in trolling success. That goes double for crankbait trolling applications. Line diameters in particular play a major roll in how deep crankbaits will dive on various lead lengths. Thinner lines create less friction and in turn allow crankbaits to achieve greater trolling depths. Thicker lines create more friction, in turn reducing the diving depth of crankbaits.

​ The problem is thin lines can also mean marginal break strengths, so anglers are forced to make the best compromise. Understanding this fundamental part of trolling is important, but as they say the devil is in the details.

​ In this case the details are a little sketchy because the manufacturers of fishing line have not adhered to any particular industry standards when it comes to line diameter as it relates to line strength. One manufacturer’s 10 pound test might come in at .011 diameter, while the next could be .014 in diameter. Not surprisingly the actual break strengths of these lines is also all over the board.

​ Breakthroughs in modern chemistry and co-polymer line formulas have allowed line companies to make thinner lines with greater break strengths than ever before. This is a good thing, but it sure confuses the heck out of anglers who figure everyone’s 10 pound test is going to be about the same size in diameter, feature a similar break strength and offer similar handling properties. Unfortunately, that’s not the situation and not by a long shot.

​ To a serious troller the pound test of a fishing line should be less important than the line diameter. The reason this is true is because line diameter can be measured, confirmed and replicated. Checking the break strength of fishing line is a little more complex because fishing knots fail at different degrees of pressure and different lines also have different tensile strengths. To get an accurate measure of a line’s true break strength requires special tools that the average angler doesn’t have access to.

​ So the “pound test” rating on a package of fishing line has become a friendly guideline, not the gospel by any stretch of the imagination. By comparison, the line diameter posted on a package of fishing line is likely to be accurate and can be confirmed easily with a micrometer.

​The other interesting, but confusing feature of modern fishing lines is they tend to be stronger than the “pound test” rating on the package might suggest. It’s not uncommon for a line posted to be 10 pound test to actually feature a break strength of 14 or even 17 pounds of pressure! This occurs because fishing line manufacturers are in competition with one another and they are constantly trying to convince consumers that their line is “tougher” or “less likely” to break. Whole marketing campaigns are built around the “marketed strength” of a particular line.

​ So it’s fair to say that some exaggeration is involved in fishing line specifications. It’s up to the consumer to wade through the “exaggerations” and come to a conclusion what line(s) happen to be best for various trolling applications.

Mark and Mari Romanack enjoy the fruits of their labor, doing a little walleye trolling on Saginaw Bay.


​ Nylon monofilament lines have been on the market for decades and this line type continues to be very popular among trollers. Monofilament has some unique properties that play well for trolling situations.

​ For one, monofilament has a controlled amount of stretch that gives the line the ability to take a lot of abuse without failing. When a powerful fish makes a run, monofilament stretches and acts like a shock absorber. The net result is a line that is tough to break and capable of tiring out powerful fish quickly.

​ Monofilament line is also round in shape making it load smoothly, evenly and tightly on reel spools. This is important because the drag system on a reel won’t function properly if the line is bunched up on or loose on the spool.

​ Monofilament also can be tied using a host of different fishing knots that are easy to master and strong. Knot strength is important because if a line fails, it’s most likely to fail at the knot. Monofilament is the most forgiving of all line types when it comes to knot strength.

​ Affordability is also one of the key properties of monofilament fishing line. Because the cost is modest compared to other line types, an angler can easily afford to load a lot of different reels which is one of the biggest reasons trollers who routinely fish with a bunch of lines often favor monofilament.

​ All of these features are good, but not all nylon monofilaments are created equal. Some monofilaments feature a hard exterior that creates a more abrasion resistant line and also a line that is best suited to baitcasting and level wind style reels. The body or memory on these lines make them a poor choice for use on spinning reels. Berkley XT (extra tough) is a good example of a monofilament that is stiffer and features a lot of memory.

​ Other monofilaments are formulated to be softer and feature less memory. Berkley XL (extra limp) would be a good example of a line that features less memory.

​ So of these two categories of nylon monofilament, which is the better choice for trolling? That depends. Most anglers would opt for a stiffer and tougher line such as a 10 pound test XT for trolling. Some trollers prefer a softer line with more stretch such as Berkley XL because the line is more forgiving, especially with powerful fish that are thrashing wildly at the boat.

​ By bumping up to a 14 pound test Berkley XL line, many feel they have the best of both worlds, including a higher break strength than a 10 pound line, but a line diameter similar or the same as many 10 pound lines.


​Truth be told, not many anglers could simply look at two lines and tell if one is a monofilament and the other a co-polymer. The chemical formulas of these two different line types are similar, but co-polymers tend to be thinner, stronger, offer more abrasion resistant and also better handling characteristics.

​It could be said that co-polymer lines are like monofilament on steroids and that would not be far from the truth. The primary down side to co-polymer lines is cost. Compared to monofilaments, the typical co-polymer is going to cost 40% or even 50% more money.

​ Co-polymers are popular with a lot of trollers because they tend to be tougher and more abrasion resistant than monofilaments. Guys who troll using planer boards will notice this immediately because putting a planer board on and taking it off the line at the same spot over and over again will soon cause damage to monofilament lines. Co-Polymer lines like Maxima Ultra Green, P-Line CXX and Sunline SuperNatural are good trolling lines that tend to have much greater abrasion resistance than garden variety monofilaments.


​ The introduction of fluorocarbon line has given trollers yet another viable option. Fluorocarbon line is very difficult to see in the water, making it a nearly invisible connection between line and lure. Fluorocarbon line is also much more abrasion resistant than monofilament line and also co-polymer lines, which makes it a good choice for fishing cover or when pinch pad style line releases are involved.

​ Most fluorocarbon lines also have less stretch than associated with nylon monofilament or co-polymer lines. Less stretch translates into better hook setting power. Many anglers are convinced that trolling with fluorocarbon line helps them hook and land more fish. This is debatable because as fluorocarbon gets wet, it has more stretch than when dry.

​ Anglers also believe that because fluorocarbon line absorbs water, that it sinks and allows crankbaits to dive deeper. Actually, this isn’t true. Fluorocarbon lines are more “neutral buoyant” than fast sinking and in the real world of trolling they don’t allow baits to achieve greater diving depths.

​ The down side of fluorocarbon lines is again the cost. Fluorocarbon costs even more than co-polymer lines making it cost prohibitive for some anglers. Also, when fluorocarbon is nicked or damaged, it’s more likely to fail than monofilament or co-polymers that have a little more stretch and forgiveness. The benefits of fluorocarbon favor using this line as a leader material instead of as a main line for most trolling situations.


​ Both fused and braided super lines have carved an important niche in the trolling world. More and more anglers feel that the thin diameter of super lines and the low stretch characteristics make them the perfect trolling line.

​ Without question thinner lines allow lures to dive deeper and that feature is an advantage in many trolling situations. The low stretch characteristics of super lines helps hooks to penetrate deeper, but that is not always an advantage. Sometimes the lack of stretch in super lines literally tears hooks free from tissue allowing fish to escape in the process.

​ Another concern regarding super lines is they are not exactly user friendly when it comes to line releases with rubber pinch pads commonly used with planer boards. Anglers who opt for using super lines will also have to invest in trolling line releases and clips designed to function with these low stretch lines.

​ Because super lines have near zero stretch, they tend to give crankbaits a more pronounced action at relative speeds. While it’s difficult to look at a crankbait fished on super line and notice a difference in the lure’s action, less stretch in the line translates to putting more pressure on the pull point (line tie attachment point) which in turn forces the lure to work harder.

​Some trollers consider this low stretch and enhanced action discussion to be an advantage. Other trollers argue that too much action can be a bad thing, especially early and late in the year when trolling in cold water conditions where a subtle action is often the best action.

​ This debate is not likely to have a definitive conclusion any time soon. It seems every avid angler has a strong opinion on the subject of using super lines for trolling.

​ One thing about super lines can not be debated. Super lines tend to last much longer than any other line type. While super lines are expensive, many anglers find they can get two or even three seasons use from reels loaded with super line. Monofilament, co-polymers and fluorocarbon can’t even come close to delivering that kind of longevity.

Trolling is a game of numbers. The most successful trollers are those who understand how important it is to know where in the water column your gear is running. Anglers who troll without the benefit of the Precision Trolling Data app are literally fishing blind and hoping for a positive result.


​ If it were not for the Precision Trolling Data app, anglers would be using all sorts of line types and diameters for trolling. Because the PTD app focuses their testing efforts on a handful of line diameters, these specific lines have become the obvious choice of serious trollers who see value in accurately controlling the diving depth of their lures and trolling gear.

​ While it would be nice if the PTD app offered Dive Curves for all the common line diameters and line types, it’s simply not practical to test all those lures and trolling devices on multiple lines. The PTD app is created by testing specific lures, lines and lead lengths and actually pulling this gear past a scuba diver who confirms the diving depth by measuring the depth using a tape measure suspended in the water.

​ It takes hours and hours to do the testing, replicate the results and document the diving depth of popular lures and trolling gear. Every lure or device that appears in the PTD app is actually tested on the water. No mathematical equations are used to speculate diving depths.

​ A few crankbaits in the PTD app are tested on multiple sizes of monofilament, but most are tested using Berkley XT 10# test with a .014 diameter. Trollers however don’t have to use Berkley XT 10# test to replicate the PTD data. Any other brand or type of line that is also .014 in diameter is going to deliver the same results as fishing Berkley XT 10#.

​ A few alternative lines to consider would be Maxima Ultra Green in 12# test, P-Line CXX in 10# test, Berkley Sensation in 14# test, Berkley XL in 14# test, Berkley Big Game in 12# test and Sunline Super Natural in 16# test. All of these lines spec out at .014 in diameter and there are many others on the market.

​ Anglers can also substitute super braids that also feature a .014 diameter. The majority of the super line brands offer either a 30# or 40# test line that specs out at .014 in diameter providing more options. Most fishing line manufacturers publish the diameter of their lines on the package. Those that don’t typically offer a line diameter chart on their web pages making it easy to look up the line diameter of just about any line type or brand on the market.


​It could be said that advancements in fishing line types has been a boom to the avid angler. It could also be said that thanks to all these different lines and marketing claims, the waters have become more than a little murky!

​ The good news is that anyone who wants to do a little research can quickly cut through the marketing BS and arm themselves with the facts associated with fishing lines. Knowledge is a powerful thing, especially when it comes to picking fishing lines for trolling applications.


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