Choosing the right length for your boat mooring lines
→ Boat mooring lines, how to choose?
A mooring line is the rope used to hold a boat in place by attaching it to a fixed point such as a quay, pontoon or deadweight. We recommend at least 4 mooring lines to keep your boat properly moored. Our practical guide will help you refine your choice of boat mooring lines and accessories according to your needs and sailing schedule.
A good must be elastic to absorb the shocks associated with your sailboat's movements, break-resistant to guarantee safety, flexible for easy handling, and durable against wear, UV and weather. We recommend choosing sturdy boat mooring lines adapted to the size of your boat to ensure comfort and longevity.
→ What length of mooring lines should I choose?
It's advisable to have at least 4 boat mooring lines on board. Calculating the size of the 4 mooring lines you need is relatively straightforward. You'll need 2 mooring lines the same length as your boat and 2 lines 1.5 times the length of your boat.
Example For a 12-meter boat, you'll need 2 12-meter mooring lines and 2 18-meter mooring lines. This covers all the mooring methods described in our guide to .
→ How to recognize a quality mooring line?
Before choosing a mooring line for your boat, it's essential to know how to identify the characteristics that guarantee its quality, strength and durability in all conditions.
➡️ Breaking strength
This is an essential criterion for guaranteeing the boat's safety, particularly in strong winds, rough seas or in your absence. A good must offer sufficient breaking strength to withstand stress, even when worn. The larger the diameter of the mooring line, the greater its resistance, and it's advisable to be generous in this respect. Choosing a sturdy mooring line, adapted to the size of your boat, will prevent any failure. You can find the breaking strength in the size guides of our online product sheets.
➡️ Elasticity
The elasticity of a mooring line is what enables it to absorb the jolts caused by wind, waves, chop and currents. Good elasticity prevents forces from being transmitted directly to the cleats or fairleads, taking the load off the fittings and improving comfort on board. For good shock absorption, attention must be paid to the type of material, the construction of the and the accessories used.
➡️ UV and scratch resistance
Mooring lines are subject to a wide range of external stresses, particularly UV rays and chafing, which reduce their lifespan. Sun, salt and weather damage fibers, especially when they are left in place for long periods. Scuffing, meanwhile, is often unavoidable: rubbing against a bitt, a neighboring guard or a part of the boat. It is therefore important to choose resistant to these stresses, while remaining flexible, easy to tie and handle.
Which fiber to choose for mooring lines?
The boat mooring lines available on the market are made of different fibers. You can find polyamide or polyester (i. e. nylon) and polypropylene mooring lines .
Polyester fiber is used for its durability, while polyamide fiber is preferred for its elasticity. Less commonly used, polypropylene fiber is known for its buoyancy.
→ Polyester mooring lines
Polyester is the all-purpose fiber. Known for its great strength in boating, Malo Motion's Dock Malo double-braided polyester mooring line has a remarkable lifespan.
Last but not least, the drying qualities of this fiber make it a highly appreciated material. A polyester mooring line is ideal for keeping your boat moored for long periods while you're away, for a rope tied to a chain to extend a mooring line.
In addition to a , a rubber shock absorber or galvanized steel spring shock absorber compensates for polyester's lower elasticity than polyamide.
→ Polyamide mooring lines
Polyamide or nylon has an elongation of between 15% and 20%, depending on the brand, and offers greater elasticity than polyester. In other words, a allows you to absorb repetitive shocks and avoid buying mooring line shock absorbers to keep your sailboat stable alongside the dock.
However, polyamide wears more than polyester rope, and over time loses some of its strength. Rest assured, however, that the brands are working to eliminate these defects day by day. For example, the double-braided structure of Malo Motion's Flexi-Malo boat mooring lines makes them far more durable.
→ Polypropylene mooring lines
Polypropylene is a hydrophobic, buoyant fiber. More generally used for towing, polypropylene can be used for special moorings: pulling a hawser ashore while swimming, throwing a boat mooring line without the risk of getting caught in a propeller.
However, keep its disadvantages in mind when using it: UV sensitivity, low breaking strength. In which case, a 3-strand Plastimo is just what you need.
→ What diameter for boat mooring lines?
Easier to calculate than cross products, determine the product you need to order and add 4 to the length of your boat to get the diameter boat mooring rope you need.
Example: your boat is 18 meters long, 18+4 = 22, so you'll need 22 mm diameter ropes.
The calculation method is designed to precisely determine the circumference to choose for your ropes, and we recommend this technique. Nevertheless, here's a general table to give you an idea of the diameter of the boat-length mooring line to choose for your sailboat, catamaran... and the fiber making up the line.
→ Why splice boat mooring lines?
A splice offers much greater strength than a knot. If you have a dedicated pontoon berth, it's a good idea to use mooring lines spliced with stainless steel thimbles, fixed in place with shackles. Having said that, it's also a good idea to use a thimble-finish on on-board mooring lines, as in certain situations, such as attaching to a dock or trunk ring, the use of a shackle can prove very useful: resistance will then be much greater than with a simple bowline knot.
→ Which accessories for your mooring lines?
There are several types of hooks and fastening systems to keep your boat mooring lines always ready for use and easy to access. Depending on the model, they can be attached to different parts of the boat, such as the stern pulpit or bow. They can also be installed directly on the pontoon, to prevent the mooring lines from dragging on the ground, and to grab them more quickly when maneuvering. A also helps to limit jerking and wear on boat ropes.
