Diameter: One thing we look for when checking quality of a fishing line is how closely does the product's actual diameter compare to what is printed on the label or advertised by the manufacturer on their website. This number can vary by quite a bit sometimes. Seaguar Tatsu at twelve pound (12lb) test is specified as 0.285mm in diameter. Using our micrometer, we tested the line in five different spots and came up with an average of 0.292mm - a difference of 0.0066mm. We've found a rough average to be in area of 0.01mm .

It casts and pitches more like nylon monofilament than traditional a fluoro.

Cast/Pitch: As mentioned earlier, a lot of fluorocarbon lines and really, most of the higher end versions, are very stiff and don't necessarily spin off the spool of your reel very easily. It's the reason Shimano's JDM Digital Control casting reels have different settings for braid vs mono vs fluorocarbon - they all behave differently during a cast. Seaguar Tatsu is the easiest casting, high end fluorocarbon we've tested. It's almost as soft and supple as a nylon monofilament and certainly as manageable as many of the softer, lower end fluoros we've used.

Yet sensitivity remains top notch.

Sensitivity: One of the benefits of that typical stiffness in higher end fluorocarbon lines is that inherent characteristic in the material allows it transmit vibrations very easily. The softer the fluorocarbon, typically, the less sensitive it is.

Seaguar Tatsu strikes an excellent balance between manageability and sensitivity which is the reason it's become one of our favorite lines to use during testing and just fishing in general.

How often to you check your line to retie?

Abrasion: In our view, a couple different factors play into abrasion. The first is obvious and that's how well the line holds up when it's rubbing across a rough surface, but possibly more important is how often do you have to retie your bait in the middle of a fishing catching frenzy.

Tatsu can lull you into bad retying habits.

Do you check your line after each catch to check for nicks that can weaken your line? Everyone knows you should, but how many actually do this? I forget all the time, yet with Tatsu, the actual need to retie is much less frequent than normal - even when using 4 or 6 pound test!

We often use the six, even four pound test on spinning gear..

Back at the lab, the average number of cycles each of the 15 fluorocarbon lines that formed the basis of our Fluorocarbon Performance Index (FPI) lasted on our abrasion machine was 14.9. Our lab data reveals 12lb Tatsu lasted an average of 21 cycles - the highest average out of the 15 lines we tested.

The heavier test Tatsu is great for use as leader material tied to braid.

Knot Strength: Knot strength is always a tricky attribute to test. On the one hand, you can compare against the line's rated strength, on the other, you can test against the line's tested breaking strength in the lab - which is almost always different than a line's rated strength.

Finesse applications in general are easier to fish with fluoro.

Well, our 12lb Tatsu broke, on average at 13.6lbs in the lab during our straight tensile tests, and at 11.2 lbs on average during the knot tests. That's a knot strength of 93% against the line's rated strength and 82% against the line's tested strength as compared to an average across our 15 baseline fluorocarbons of 65% and 71% respectively.

How do you fish braid with swimbaits? Tie on a fluoro leader with a top end product like Tatsu.

Next Section: How does Tatsu handle?