Boat Rope & Boat Line

What are boat lines?

- Lines for boats - numerous varieties and applications -

All the mobile rope used to raise, lower and trim the sails on board is known as running rigging. These boat lines comprise a wide range of different types of ropes used on ships. Halyards, for example are used to control the sails, whereas mooring rope holds the vessel in place at quays, wharfs, jetties etc. Sheets or trim lines control the direction of the sails, anchor lines make sure your boat stays in place, and tow lines are used to pull other boats. Each type of running rigging requires a line material with very specific composition in terms of strength, elasticity and abrasion resistance. Buoyant rope is a must for some applications, other lines are better if they sink. So, before you buy any boat line for your running rigging, you should first know how it will be used and take the above factors into consideration.

We provide a comprehensive overview here to help you decide. Whatever type of line you require for your running rigging, we have the best rope for you, including halyards, sheets (also pre-spliced), trim lines or tow lines, bungee cord as well as boat lines with carabiners. We can also custom-make lines according to your requirements in terms of length or load bearing capacity. And furthermore, our ropes can be used in all kinds of outdoor activities, not just in sailing.

What are the different lines on a boat?

- The type depends on the use -

Mooring lines: What makes good mooring rope? They have to secure your boat fast to her berth over long periods of time and in severe weather. This kinds of rope must be strong, chafe and UV resistant, with high breaking loads and excellent elasticity. In your home marina, lines should be an appropriate length, to reduce annoying squeaks, rattles or chafing. For this reason, experts recommend spliced lines with a thimble or eye, in a length that is perfectly matched to the berth.

Sailboat lines that are spliced with a thimble or eye are much stronger than lines that are tied with a knot. In fact, a knot reduces the strength of a line by up to 75%. The material strength of lines that are spliced with an eye or thimble can therefore be kept low. They also make it easier to attach a rope to a ring on the jetty, around a bollard or to a mooring dolphin.

Sheets: Sheets are attached to the sails' clews and can be controlled by 'trimming' them and adjusting the sail to the wind. The demands on these lines are high because they are frequently subjected to extreme stresses. Strength and handling is important, as is abrasion-resistance, which should all be at the highest level. Sheets on modern sports or leisure sailboats are frequently made of braided synthetic fibres, most notably polyester or dyneema. A braided cover or sheath protects the load-bearing core. Tightly braided, abrasion-resistant, low stretch fibre material with a Dyneema core and polyester or Dyneema sheath is ideal in regatta sailing. In dinghy sailing, on the other hand, good grip is very important, as is flexibility, light weight and strength.

Halyards: The lines used for halyards should also be as resistant as possible to salt water, abrasion and UV light. Strength is also important, as is stretch, softness in the hand and grip in jammers and clutches. Halyards are therefore usually made of a braided, low-stretch synthetic fibre such as polyester. Regatta sailors prefer to use sailboat lines made of high-strength Dyneema because of its extremely low stretch properties.

Anchor lines: These are primarily made of polyester, which has a high breaking and working load. Polyester is relatively stretch-free, but has enough elasticity to prevent "jerking". Load peaks that act on the boat and anchor in wind and swell are thus well absorbed, which prevents damage to the line and fixtures on deck. Adding a thimble spliced to the end of your anchor rope, to which a shackle can be attached is particularly important. A thimble has a much smaller effect on the breaking load of a line than a knot. Choose one made of stainless steel to prevent chafing where the shackle connects to the anchor or chain forerunner.

Towlines: These lines require high tensile strength and elongation to absorb peaks in tensile load. They must also have good abrasion resistance, flexibility and excellent grip: Tow lines are often made of polyester or the somewhat cheaper and more buoyant polypropylene. 

Telltales - Sailing telltales show the best position of the sails to the wind. Jib telltales are attached on both sides of the luff of the jib and indicate the direction of wind flow. Mainsail telltales are attached to the leech of the mainsail, usually on each side of the sail. They are made of twisted or braided material in various thicknesses, mostly high-strength polyamide fibre.

Flag lines: The more robust the material, the less often will they need to be replaced. Flag lines should be resistant to wind, sun and salt water as well as abrasion for as long as possible. Ideal material is therefore polyester or polypropylene with a core-sheath braid. A single braid is also adequate. They should have a small diameter and must above all be strong, light and elastic.

Fender lines: Fender ropes should be able to withstand damage caused by the sun and saltwater. They should also not chafe even after years of use, which is why fender lines are often made of polypropylene, polyester or polyamide. There's not much difference between twisted or braided rope. Twisted lines are just as strong as braided lines of the same diameter, but twisted line material has better stretch and absorbs dynamic loads from wind or swell better.

What are boat lines made of?

- Different properties for different applications on board -

Nowadays, synthetic fibre ropes are used on almost all boats and sailing yachts. They are strong and have varying properties that are ideal for the respective fields of application. Only traditional sailing ships still use natural fibre ropes today, and even on such vessels, synthetic ropes that resemble natural fibres are preferred because of their superior strength. Let's take a quick look at some of the properties of such synthetic fibres:

Polyester: Polyester is relatively cheap and keeps its flexibility even under heavy load. Polyester ropes are suitable as halyards and can also be used as sheets on cruising yachts.

100 % Dyneema: For high demands and constant loads, such as in regatta sports, we recommend halyards and sheets made of Dyneema. This high-strength synthetic fibre features lower stretch than polyester and is also lighter in weight. However, Dyneema is not suitable as a sheet by itself, and for halyards only in combination with core-sheath braids.

Fibre rope: These ropes are made of 20-plait polyester continuous fibres. They are particularly resistant, flexible and relatively smooth. Sheets for boats made of staple fibre yarn or worsted yarn hold well in the hand due to their soft, fluffy texture. The disadvantage is that they also wear out much faster and are not recommended for winch use. A good alternative, on the other hand, is GripFibre. Grip-fibre sheets for boats consist of specially treated continuous polyester fibres or have staple fibres incorporated, resulting in a sheath that is easy to grip but still strong.

Sheaths: Parallel-core sheaths feature a manufacturing method whereby the core fibers lie parallel to the sheath, which reduces the elongation of the rope. This process is common for polyester ropes. The construction requires an inner sheath, which often causes these lines to be somewhat stiff. Core and cover are typically made from two different braids and, sometimes other materials.

Halyards are often made with a polyester or dyneema core. The sheath is made of polyester, in part with Technora or Vectran components. Halyard rope with an inner cover has a layer of staple fibre integrated between the core and the cover (core-inner sheath-sheath). This makes the core diameter smaller and halyards run better through stoppers.

Where can I find pre-spliced boat lines? 

- Pre-spliced rope and custom-made lines -

Are you looking for custom-made marine ropes for your boat? You will find a large selection of pre-spliced boat lines with eye or carabiner in our online shop. We have partnered with GLEISTEIN to offer the most complete rope service available to our customers. Whether sheets for boats by the metre or braided rope made to measure, give us a call or fill out the datasheet and send it back to us.

Related categories: Life lines, carabiners and shackles

You can find additional products on the subject of boat ropes in other shop categories. Take a look at our Pre-spliced Halyards & Sheet Rope, Carabiners and Shackles sections. You can also find more useful information in our SVB guide "How to find the best yacht rope" or find out what to know when taking the rig in and out of winter storage.