Mooring Line & Rope Size Guide: Which Diameter Is Right for Your Boat?
Specifying the correct diameter of mooring line for your boat not only provides the appropriate safety factor but can greatly improve onboard comfort. Use too thin a line and it'll chafe through under load. Go too heavy and you're adding unnecessary weight and stiffness. This guide covers recommended mooring line sizes for boats from 15ft dinghies to 50ft+ yachts, covering both polyester 3 strand and double braid options with a simple size chart you can bookmark.
Mooring lines cover a broad range of uses, from boat specific lengths custom made for your pontoon or mooring buoy, to anchoring, swinging moorings, tidal piers & rafting up.
For custom splicing of mooring lines or for further advice please email info@rope44.com or contact us on +44 (0)1394 248 707 to discuss.
| Yacht Length | Blue Ocean Dockline | 3 Strand Polyester |
|---|---|---|
| 6m / 20ft | 8-10 mm | 8-10 mm |
| 8 m / 26ft | 10 mm | 10 mm |
| 10 m / 33f | 12 mm | 12 mm |
| 12 m / 39ft | 14 mm | 14 mm |
| 14 m / 46ft | 16 mm | 16 mm |
| 16 m / 53ft | Marina Grande Dockline* | Non Stock Item Contact for Delivery |
| 19 m / 62ft | Marina Grande Dockline* | Non Stock Item Contact for Delivery |
*Marina Grande is the suggested option for yachts requiring diameters above 16mm
This table is prepared as a guide only.
Tips
- For faster, simpler & more secure mooring operations we recommend the addition of a long loop eye splice in the end of mooring ropes
- For mooring lines attached to other hardware such as shackles or mooring rings we recommend the addition of a stainless steel thimble on the spliced eye to reduce chafe and related ware.
- For swinging moorings we recommend Octoplait - an 8 plait rope which won't unravel as 3 strand does if your swivel gets jammed.
- Wash your ropes as frequently as you can to keep them supple and remove the damaging salt crystals.