SEAGUAR FXR BOAT Fluorocarbon Mainline – 100% Fluoro | #2–#20 | 100m | Boat Fishing

The SEAGUAR FXR BOAT is a 100% fluorocarbon mainline made in Japan by Seaguar — the company that invented fluorocarbon fishing line. Available in 14 line classes from #2 (5lb) to #20 (70lb) in 100m spools. Designed as a boat fishing mainline for snapper, kingfish, reef species and jigging applications.

Seaguar — The Originator of Fluorocarbon Fishing Line

Seaguar developed and commercialised the first fluorocarbon fishing line in the 1970s. All fluorocarbon fishing lines on the market today trace the technology back to Seaguar’s original PVDF (polyvinylidene fluoride) extrusion process. The FXR BOAT is manufactured in Japan under Seaguar’s own production process — not outsourced — and uses the same fluorocarbon polymer chemistry that established the category.

What Fluorocarbon Mainline Is — and How It Differs from Nylon Mono and PE Braid

Fluorocarbon (PVDF) is a dense polymer with a specific set of physical properties that differ from both nylon monofilament and PE braided line:

• Near-invisible underwater: fluorocarbon has a refractive index of approximately 1.42, which is very close to the refractive index of water (1.33); nylon monofilament has a refractive index of approximately 1.53, which is significantly further from water’s value and therefore more visible underwater in clear conditions; the closer a material’s refractive index is to water, the less light bends at the material’s surface and the less visible the line appears to fish; in clear water over reef and in offshore conditions where fish are pressured and line-shy, fluorocarbon mainline is substantially less visible than nylon of equivalent diameter
• Zero water absorption: nylon monofilament absorbs water — up to approximately 8–10% of its dry weight after prolonged immersion — and loses 10–15% of its rated dry breaking strength when fully wet; fluorocarbon does not absorb water and maintains its rated breaking strength throughout the session regardless of immersion time; for boat fishing where the line is in the water continuously over a long session, nylon’s wet strength loss is a practical concern that fluorocarbon eliminates
• Sinking: fluorocarbon is denser than water (specific gravity approximately 1.78) and sinks; nylon monofilament has a specific gravity near neutral and floats or sinks slowly; PE braid floats; a sinking mainline keeps the line angle steeper in deep water and in current, maintaining better contact with the sinker or jig and improving bite detection; for deep reef fishing and jigging, a sinking line reduces the bellying in current that causes PE braid to float away from the target depth
• Low stretch: fluorocarbon has lower stretch than nylon monofilament (typically 20–25% vs nylon’s 25–30%) but more stretch than PE braid (near zero); in the context of boat fishing, fluorocarbon’s moderate stretch provides a shock buffer during the initial strike and head shakes of a large fish, reducing the likelihood of pulling the hook on sudden direction changes; this is an advantage over low-stretch PE braid for species that make short, violent head shakes at boat-side (snapper, kingfish)
• Abrasion resistance: fluorocarbon has higher surface hardness than nylon monofilament and resists abrasion from reef, rock and structure contact; for boat fishing over reef and rock bottom where the line makes contact with substrate, fluorocarbon maintains line integrity better than nylon under the same abrasion conditions

FXR BOAT — Designed as a Mainline, Not a Leader

Seaguar produces fluorocarbon in two distinct categories: leader materials and mainlines. The FXR BOAT is a mainline product — it is engineered for the flexibility, casting performance and spool-ability required when filling a reel spool, not for the short-length, maximum-stiffness applications of leader fluorocarbon. Fluorocarbon leaders are typically stiffer and produced to tighter diameter tolerances for abrasion performance at the terminal end; a fluorocarbon mainline is softer and more supple for smooth casting and even spool layering. Using a leader-grade fluorocarbon as a mainline results in a stiff, wiry spool that creates memory coils; the FXR BOAT’s mainline formulation eliminates this.

Line Class Guide — Japanese # System and lb Equivalents

The FXR BOAT uses the Japanese 号 (go/gō) line class system alongside the lb breaking strength rating. The # number is a standardised diameter/weight class — each increment corresponds to a specific diameter and approximate breaking strength in the Japanese JIS standard. The lb figure is the rated breaking strength in pounds.

• #2 / 5lb — lightest class; light boat fishing for bream, small snapper and whiting in shallow reef and bay environments; suits 1000–2500 spinning reels
• #2.5 / 10lb — light snapper and reef species; suitable for light boat jigging and bait fishing in 20–40m depth
• #3 / 12lb — general light reef fishing; snapper to 3kg, bream and smaller reef species from boat in moderate depth
• #4 / 16lb — mid-light snapper and reef; suitable for paternoster rigs and slow jigging in 30–60m over reef
• #5 / 20lb — general boat fishing mainline; versatile for snapper, pearl perch and reef species in 30–80m; the most common all-round boat fishing class in this range
• #6 / 22lb — heavier snapper and early kingfish; suitable for deeper reef fishing and live baiting for kingfish to 10kg
• #7 / 25lb — kingfish and large snapper; bottom fishing in 50–100m with heavy sinker rigs
• #8 / 30lb — heavier kingfish and reef species; slow jigging and bottom fishing in deep reef; suits medium spin and baitcast boat outfits
• #10 / 35lb — heavy boat fishing; large kingfish, amberjack and deep reef species; heavy jig applications in 80–150m
• #12 / 40lb — heavy game boat fishing; large kingfish and tuna; suits overhead reels in the 6000–8000 class
• #14 / 50lb — big game; southern bluefin tuna and large kingfish from boat; heavy overhead outfit
• #16 / 55lb — heavy big game; suitable for heavy bottom fishing in deep water and large pelagics on overhead game outfits
• #18 / 60lb — very heavy; dedicated big game and heavy boat applications; suits large overhead reels (Penn Senator, Shimano Tiagra class)
• #20 / 70lb — heaviest class available; maximum class for heavy bottom fishing, shark and large pelagic applications; suits full-size game overhead reels

Specifications

• Brand: SEAGUAR
• Series: FXR BOAT
• Material: 100% fluorocarbon (PVDF)
• Origin: Japan
• Length: 100m per spool
• Line classes: #2 to #20 (5lb to 70lb)
• Type: Mainline (not leader)
• Buoyancy: Sinking