A good mooring line is crucial for keeping your boat securely moored at the dock. The wrong line can break in a storm or damage the boat's hull. Here's everything you need to know to make the right choice.
Material – what should you choose?
- Polyester – Low stretch, high durability, UV and saltwater resistant. Best for permanent mooring
- Nylon – High stretch that absorbs shocks and jerks. Excellent for anchoring and in tidal areas
- Polypropylene – Floats on water, inexpensive but sensitive to UV and wear. Suitable for temporary use
- Dyneema/Spectra – Extremely strong and light, minimal stretch. Used on racing boats and in demanding environments
How do you choose the right thickness?
The line's diameter should be adapted to the size of the boat:
- Up to 6 m boat → 8–10 mm line
- 6–9 m boat → 10–12 mm line
- 9–12 m boat → 12–16 mm line
- Over 12 m → 16 mm+ line
Length of the line
- Mooring lines should be at least 1.5 times the length of the boat
- Use at least four lines for secure mooring: bow, stern, two spring lines
- In exposed locations or in bad weather – use extra lines
Construction – twisted or braided?
- Twisted line – Traditional, easy to tie and repair. Slightly more stretch
- Braided line (double braided) – Softer, easier to handle, lower stretch. Recommended for most boats
- Cable-laid line – Very strong but stiff, rarely used on pleasure boats
Care & lifespan
- Rinse lines with fresh water after use in saltwater
- Regularly check for wear, degraded fibers, and UV damage
- Store lines dry and protected from direct sunlight
- Replace lines showing signs of severe wear – a broken line can cause serious damage
Buying tips
- Always choose certified lines with stated breaking strength
- Buy lines with pre-made loops (spliced ends) for easier handling
- Use mooring compensators (snubbers) to reduce jerks and strain on cleats
