Seachoice 40820 Twisted Nylon Rope 5/8" x 600'

Heavy-Duty Twisted Nylon. 5/8" Diameter. 600 Feet for Large Vessel Applications.

The Seachoice 5/8" x 600 Ft. Twisted Nylon Rope Spool is the heavy-duty bulk line choice for large vessels, commercial dock applications, and high-load mooring setups where smaller diameters simply aren’t enough. Made from 100% filament nylon fibers, this twisted 3-strand rope delivers exceptional elasticity and shock load absorption — the properties that make nylon the preferred material for dock lines and anchor rodes on larger boats where surge forces can be significant.

Twisted construction is the traditional marine rope format — easy to splice with standard tools, easy to inspect for wear, and proven over decades of marine service. At 5/8" diameter, this is a serious working line with the working load to match vessels in the 45-foot-and-up range, and the chemical resistance to hold up in demanding dock and marina environments.

Key Features

• 100% Filament Nylon — Superior elasticity and shock load absorption vs. polypropylene or polyester; the standard for dock and anchor lines
• Twisted (3-Strand) Construction — Traditional marine rope format; easy to splice, inspect, and work with standard tools
• 5/8" Diameter — Heavy-duty sizing for large vessels (45+ ft) and high-load dock, mooring, and anchor applications
• 600-Foot Bulk Spool — Cut to any length needed; ample supply for a full marina inventory or multiple large-vessel dock lines
• Excellent Shock Load Absorption — Nylon stretches under surge loads to protect cleats, dock hardware, and hull fittings
• Abrasion Resistant — Filament nylon construction withstands chafe against dock edges, cleats, and chocks
• Resistant to Rot, Mildew, Oil, Grease, Gasoline, Acids & Most Chemicals — Built for long-term service in demanding marine and industrial environments

Specifications

• Brand: Seachoice
• Construction: Twisted (3-Strand)
• Material: 100% Filament Nylon
• Diameter: 5/8" (15.9mm)
• Length: 600 ft (182.9m)
• Weight: 26.3 kg (58.0 lb)
• Part Number: 50-40820

For large vessel owners, marina operators, and commercial dock facilities that need a premium bulk supply of heavy-duty nylon dock line, the Seachoice 5/8" twisted nylon spool is the professional-grade choice.

⚓ Parts Desk Insight

• 5/8" is for large vessels — confirm sizing before ordering: This diameter is typically used on vessels 45 feet and larger. Customers with mid-size boats (30–45 ft) are usually better served by 1/2" line; smaller vessels by 3/8". Oversizing dock lines adds unnecessary weight and bulk without meaningful safety benefit.
• Twisted vs. double braid — splicing is the key difference: Twisted 3-strand rope is easier to splice with basic tools and is the traditional choice for eye splices on dock lines and anchor rodes. Double braid requires a different splicing technique and specialized tools. For customers who splice their own lines, twisted is the more accessible construction.
• Filament nylon vs. staple nylon: Filament nylon is made from continuous fibers, giving it higher strength, better abrasion resistance, and a smoother surface than staple (spun) nylon. This is the higher-quality specification for marine dock line applications.
• Bulk spool — cut and splice ends properly: At 5/8" diameter, heat-sealing alone is not sufficient for finished dock line ends. A proper back splice or whipping is recommended to prevent unraveling, and an eye splice at the loop end is the professional standard for dock lines at this size.