Store Update: We are open for business! Due to ongoing phone issues, please email if you are unable to reach our team. We appreciate your patience.

Category Banner

Dyneema, Spectra & Vectran


Spectra and Vectran line have extremely low stretch and are perfect for performance applications such as travelers or as part on a control set up.

Dyneema, Spectra & Vectran Sailing Line

If you're looking for line with near zero stretch, then our selection of Dyneema, Spectra, and Vectran lines are for you! These high tech lines have near zero stretch and perfect for performance applications such as travelers or as part on a control set up. These lines are uncovered and more likely to wear, but do feature UV coating to protect from sun damage.

Low Stretch Lines Explained

Dyneema & Spectra

Dynema® and Spectra® are made from UHMWPE (Ultra High Molecular Weight PolyEthylene), a long chain, high strength, oriented strand, synthetic fiber with very high strength and high abrasion resistance. This fiber is also known as HMPE (High Modulus PolyEthylene).  Dynema® is the Dutch company DSM Dyneema's brand of UHMWPE, used by Samson in their Amsteel and Amsteel-Blue dyneema lines. Honeywell International produces a similar UHMWPE fiber, marketed as Spectra®. Both Dyneema (Dynema) and Spectra offer nearly identical characteristics are can be used interchangeably in sailing applications, depending on where you source your line.


Made from a LCP (liquid crystal polymer) fiber, Vectran exhibits high strength, excellent creep and abrasion resistance, excellent flex/fold and chemical resistance, and outstanding heat and cut resistance. Vectran is an alternative to Dyneema or Spectra and less stretch and creep. Many think Vectran is the ultimate fiber, though it does not have quite the fatigue life or UV resistance of Dyneema or Spectra. Also it is a little heavier and will not float.

Common Applications

Dyneema, Spectra, and Vectran lines are recommend for use in applications where low to zero stretch is the core requirement. It's common to see these lines used as halyards, in sail control line systems, as travelers, or even as replacements for wire rigging in some performance applications. Since most low stretch Dyneema, Spectra, and Vectran lines are a single-braid without a cover, they are not recommended for applications where the line needs to be cleated and uncleated often. In those use cases you'll want to consider a line with a cover, such as a high performance dyneema or spectra core line with a heavy duty polyester cover.

Finding The Right Diameter

If you are replacing an existing line, the easiest way to determine what diameter you need is to match what you already have. This can be done with a caliper or by close estimation with a tape measure. If you've previously used a 7mm sheet and it has performed well, another 7mm line is likely a great choice. In most applications, there is some flexibility in the exact diameter that can be used. Most blocks, for example, have an 'ideal' diameter (ie, the line diameter that runs most effectively though the block's sheave) but also have a range so that you can run a slightly thinner or slightly thicker line. If you have a sheet that is getting hung up in your rig, stepping down 1-2mm might help the sheet run more efficiently. If you have a larger boat or rig and want to run a thinner sheet, consider a double braid line that features a Dyneema or spectra core for strength.

Line Diameter Conversion

1mm = 3/64 inch | 2mm = 5/64 inch | 3mm = 1/8 inch

4mm = 5/32 inch | 5mm = 3/16 inch | 6mm = 1/4 inch

7mm = 9/32 inch | 8mm = 5/16 inch | 9mm = 3/8 inch

10mm = 25/64 in | 11mm = 7/16 in  | 12mm = 1/2 in

Double Braid vs Single Braid

Two terms you will often see in line descriptions are 'double braid' and 'single braid', which refer to the way the line is constructed. At the most basic level, a double braid line has a cover and a core whereas a single braid does not, but there are other important distinctions to consider when making a line selection.

Single Braids are made up of either 8 or 12 strands that are braided into a circular pattern, half clockwise and half counter clockwise. This produces a line that is supple, absorbs twists, and tends not to kink. There are two types of single braid lines: performance single braids and polyester/blended single braids. Performance single braids are made from fibers with very low stretch and designed to handle extreme loads - think Dyneema, Spectra, or Vectran. Polyester/blended single braids, sometimes called hollow braid, are soft and easy to grip, built for sheets and hand-adjusted control lines. These are less common than performance single braid lines but recommended in a few specific applications.

The Dyneema, Spectra, and Vectran lines on this page are Single Braids. The exception is the Robline Dinghy Vectran, which has a Vectran core.

Double Braids, sometimes called braid on braid, have a braided core within a braided outer jacket or cover. This creates a strong, durable, smooth-running line that is easy to handle. Double braids are used for the vast majority of all running rigging on sailboats including sheets, halyards and control lines for both cruising or racing. There are two types to consider: polyester double braids and high-tech double braids. Polyester double braids, found most commonly on recreational and cruising sailboats, have a polyester cover with polyester core. These are low maintenance, affordable, and long-lasting, while offering relatively low stretch and high working loads. For additional strength and minimal stretch, consider high-tech double braids. These lines typically feature a Dyneema or Spectra core (non-stretch) inside a polyester or polyester/dyneema blend cover for additional durability. They are more expensive but often the go to choice for high performance racing boats.

Whipping & Splicing

Looking to clean up the end of your line or need to add a splice to your rig? Visit our Whipping & Splicing page for a full selection of whipping twine, fids, splicing needles, and complete splicing kits. Perfect for the DIY sailor looking to further optimize their rigging.