Elastic Polyester Shock Cord, 4–10 mm – Extra Durable Bungee Rope

This elastic polyester rope (also known as shock cord or bungee cord) is a must-have accessory for any boat or camping setup. It consists of a core made from multiple rubber/latex strands, which provides a high degree of stretch, and a tough outer layer of braided polyester that resists UV radiation, abrasion, and shields the inner elastic material. The result is a cord capable of stretching to roughly double its length (or more, depending on the spec) and then retracting back, exerting a constant pulling force.

Onboard Uses: The elastic rope has countless applications on a boat. You can use it to secure a tarp or cover – the bungee effect keeps the cover taut and compensates for the boat’s motion. It works excellently as a cargo tie-down – for example, strapping down gear, life jackets, or fuel tanks so they don’t shift when you’re in waves. In rigging, where some give is desirable, shock cords are employed to hold lines in place with tension but allow flex (for instance, keeping a tiller centered, holding halyards snug but not rigid). It’s also useful for making quick holders – e.g., elastic loops for fishing rods, paddles, or other items you want to keep in place yet be able to release quickly.

Durability & Advantages: The polyester sheath on this cord ensures it withstands intense sun and saltwater without fraying or losing elasticity prematurely. Even after extended use, the cord retains most of its “spring” thanks to the high-quality rubber core. The different diameters let you choose the right bungee for the job: 4 mm is great for light tasks (like small lashing or flag staffs), 6–8 mm are general-purpose for securing gear and tarps, and the 10 mm version can handle heavier loads (e.g., holding an outboard motor to a rail or other substantial equipment).

When using shock cord, it’s always good practice not to overstretch it to its limit for long periods – this will prolong its lifespan. If you need to hold something in place long-term, go for a thicker diameter or use the cord in a more relaxed state so it has reserve stretch for any surges (for example, in a gust of wind).