Mooring Line Size Guide - Suggested Size & Type by Boat Length

Specifying the correct size of mooring line for your boat not only provides the appropriate safety factor but can greatly improve onboard comfort. 

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 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 / 33ft 12 mm 12 mm
12 m / 39ft 14 mm 14 mm
14 m / 46ft 16 mm 16 mm
16 m / 53ft Marina Grande Dockline* No 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. 


  • 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.