Seachoice 42780 Solid Braid 100% MFP Mulit-Purpose Rope Spool, 3/8 in x 500 ft, Blue and White

Floats. Resists Rot. 500 Feet of Multi-Purpose Polypropylene.

The Seachoice 3/8" x 500 Ft. Solid Braid 100% MFP Multi-Purpose Rope Spool is built from monofilament polypropylene (MFP) — a material that floats, resists rot, and shrugs off marine growth, making it a practical choice for tow lines, ski ropes, safety lines, utility rigging, and any application where a buoyant, low-maintenance line is an advantage. The blue and white colorway makes it easy to spot on the water and gives it a clean, nautical look on deck.

Solid braid construction keeps the line round and firm under load, feeding cleanly through blocks and hardware without flattening. At 3/8" diameter and 500 feet per spool, this is a versatile bulk supply for boaters, marina operators, and anyone who needs a reliable multi-purpose line in quantity.

Key Features

• 100% MFP (Monofilament Polypropylene) — Floats on the surface; easy to grab and recover if dropped overboard
• Solid Braid Construction — Maintains a firm, uniformly round profile under load; feeds cleanly through blocks and hardware
• Rot & Marine Growth Resistant — Polypropylene does not absorb water and resists rot, mildew, and marine growth
• Multi-Purpose — Suitable for tow lines, ski ropes, safety lines, dock lines, anchor lines, and general utility rigging
• 3/8" Diameter — Practical mid-size diameter for a wide range of marine and utility applications
• 500-Foot Bulk Spool — Cut to any length needed; ample supply for multiple lines or a full season’s use
• Blue and White — High-visibility colorway; easy to spot on the water and clean-looking on deck

Specifications

• Brand: Seachoice
• Construction: Solid Braid
• Material: 100% MFP (Monofilament Polypropylene)
• Diameter: 3/8" (9.5mm)
• Length: 500 ft (152.4m)
• Color: Blue and White
• Weight: 11.3 kg (25.0 lb)
• Part Number: 50-42780

For boaters who need a buoyant, rot-resistant, multi-purpose line in bulk, the Seachoice 3/8" MFP solid braid spool delivers the float, the durability, and the length to handle whatever the water throws at it.

⚓ Parts Desk Insight

• MFP floats — nylon does not: The defining advantage of polypropylene over nylon is buoyancy. For tow lines, ski ropes, safety throw lines, and any application where a floating line is critical, MFP is the correct specification. For dock lines where shock absorption and stretch matter more, nylon is preferred.
• MFP has less elasticity than nylon: Polypropylene does not stretch as much as nylon under load. This makes it less ideal for primary dock lines on larger vessels where surge loads are a concern, but perfectly suitable for tow lines, utility rigging, and applications where minimal stretch is acceptable.
• UV degradation over time: Polypropylene can become brittle with prolonged UV exposure over multiple seasons. Inspect the line annually for stiffness, brittleness, or color fading, and replace if the fibers show signs of UV degradation. Storing the spool out of direct sunlight when not in use extends service life.
• Blue and white is high-visibility on the water: The two-tone colorway makes this line easy to spot if it goes overboard — a practical safety advantage for tow lines and safety lines where quick recovery matters.