Seaguar Tatsu Fluorocarbon
Diameter chart, reel capacity & backing guide
Tatsu is Seaguar's double-structure fluorocarbon main line. Two fluorocarbon resins are combined in one line, with Seaguar emphasizing suppleness and strength. This guide covers the listed 4-25 lb sizes and helps you budget a full fill or a working section over backing.
- Construction
- Double-structure 100% fluorocarbon
- Listed strengths
- 4-25 lb
- Line type
- Fluorocarbon main line
Is Tatsu right for your setup?
Consider Tatsu when you want to cast fluorocarbon directly, especially when handling and the amount of premium line used matter to your setup. A partial fill over sound mono backing can reduce how much Tatsu is tied up below the working line. It does not remove the need to choose a manageable diameter: thick fluorocarbon can be awkward on a compact spinning spool even if the capacity number is acceptable.
How much Tatsu will fit?
Calculated estimates, not measured fills. Stop at the reel manufacturer's fill level even if some line remains.
Seaguar Tatsu diameter chart
Current Seaguar Tatsu chart and listed spool sizes. Package lengths vary by strength; inch and millimeter figures are independently published.
| Strength | Inches | mm | Spools (yd) |
|---|---|---|---|
| 0.006 | 0.165 | 200 | |
| 0.008 | 0.205 | 200, 1000 | |
| 0.009 | 0.235 | 200, 1000 | |
| 0.010 | 0.260 | 200, 1000 | |
| 0.011 | 0.285 | 200, 1000 | |
| 0.013 | 0.330 | 200, 1000 | |
| 0.014 | 0.350 | 200, 1000 | |
| 0.015 | 0.370 | 200, 1000 | |
| 0.015 | 0.385 | 200, 1000 | |
| 0.016 | 0.405 | 200 |
Choosing your Tatsu strength
Start with the lighter 4-8 lb options when considering a light spinning setup, then check your rod, cover, and drag setting. Tatsu's 4 lb and 6 lb entries are not interchangeable in a capacity calculation: their listed inch diameters are .006 and .008.
For baitcasting setups, compare the 10-15 lb choices with the demands of your lure and cover before moving into 17-25 lb. The heavier sizes are not simply better versions of the lighter line. Their extra spool volume can shorten the useful working length.
Tatsu 20 lb and 22 lb both round to .015 inch in the manufacturer chart, although their millimeter entries differ. ReelCalc's inch-based calculation will therefore give them the same capacity. That is a limit of the rounded inputs, not proof that the lines are physically identical.
This is a specification-based setup guide, not a hands-on Tatsu performance test.
Want a guided recommendation?
Continue in the Setup WizardSame pound test, different diameters
At your selected strength
Loading diameter comparisons...
What changes with another line?
Nearby diameters in the line database
| Line | Strength | Inches | Difference |
|---|---|---|---|
| Loading line database... | |||
Backing, working line & leaders
Decide how much Tatsu you need
For a full Tatsu spool, use the full-capacity result. For a shorter working section, allow for casts, fish runs, damaged-line removal, and repeated retying before assigning the remaining space to backing.
Keep backing below the working line
Mono backing sits underneath the Tatsu. Choose a working length that keeps its connection below the line you normally fish, and do not reuse backing that is damaged or slipping on the arbor.
Match the retail package
The 200-yard package is listed throughout this range. The 1,000-yard package is not listed for every strength: the current chart excludes 4 lb and 25 lb. Check your selected row before assuming a bulk spool exists.
How Much Fits on These Reels?
Estimated full-spool capacity for the Tatsu strength selected above, with no backing. These are calculated examples, not physical tests or recommendations for every pairing.
Loading capacity estimates...
Tatsu questions, answered
Is Tatsu a main line or leader material?
Seaguar sells Tatsu as fluorocarbon main line. You can use a short piece as a leader, but that does not make Tatsu the material filling a braid spool. Calculate capacity using the actual main line.
Does Tatsu have the same diameter as InvizX?
Not at every strength. For example, the current 20 lb entries are .015 inch for Tatsu and .016 inch for InvizX. Use exact product-and-strength diameters instead of treating all Seaguar fluorocarbon as one line.
Will one 200-yard Tatsu spool fill my reel?
Select your reel and Tatsu strength to check. A result below 200 yards means one full retail spool should cover that calculated fill; a higher result calls for more main line or an intentional backing plan. Stop at the reel's recommended fill level.
Specifications & sources
Specifications checked against Seaguar's listed spool sizes on 2026-09-12 and its published chart. Unassigned package combinations are excluded. Stock and package design can change; use the diameter printed on your own package if it differs.
Calculations use the catalog's listed inch diameters. Published inch and millimeter values may differ slightly because of rounding.
- Official Seaguar Tatsu specifications Product construction, diameter entries, and assigned retail package lengths.
- Seaguar Tatsu specification chart Manufacturer chart checked alongside current product variants.