Fender Size Guide

Choosing the right size fender

Take these factors into account when selecting the appropriate size for your fenders: Yacht Length Overall, Yacht Displacement (weight) and the anticipated mooring conditions

There is an old fashioned rule of thumb that will give you a starting point before making a final decision based on these three main factors.

Rule of Thumb 1 = 1 inch fender diameter or 2 inch round fender diameter for every 4 or 5 feet of yacht length overall.

The rule has been interpreted and converted approximately into modern metric equivalents in the table:

Boat Fender Size Guide
Yacht Length Overallunder 5m6m8m10m12m14m16m18m
Cylindrical Fenders Diameter100mm125mm150mm200mm250mm300mm350mm400mm
Majoni Star SizeStar 1Star 1Star 2Star 3Star 4Star 5--
Polyform F Series SizeF01LF1/F02F2/F3F3/F4F4F5F5/F6F7/F8
Round Fenders Diameter200mm250mm300mm400mm500mm600mm700mm800mm
Majoni Buoy SizeRB1RB1RB1RB2RB3--
Polyform A Series SizeA1A1A2A3A4A5A6

Frequency Guide

There is another old rule of thumb for this too – 1 fender per 10 feet of Low Waterline Length (LWL) with a minimum of 3 for boats of 20 feet or less. The rule has been developed into a modern metric measure equivalent.

Boat Fender Frequency Guide
Yacht LWLunder 6m6m-10m10m-14m14m-16m16m-18m
Fenders34567

How to set up boat fenders

Fenders need to be deployed in a proper fashion paying due care and attention to the spacing and height of the fenders and an assessment of how many of the total should be round rather than cylindrical fenders.

Deploy at least one fender amidships (maximum beam) with the remainder spaced appropriately fore and aft from the centre outward.

When mooring alongside another yacht (rafting up) an extra fender or two amidships will be required for adequate protection. An extra round fender deployed fore and aft will help to take up the increased gap between the topsides.

Hang fenders so that they are always just clear of the water or higher where required because of the pontoon height. Secure the fender lanyards to strong, deck level anchorage points. Avoid using lifelines or guard wires if possible because they are not designed to withstand the potential stresses and strains. A lower attachment point maintains the fender in position better by lessening the arc or swing.

Cleaning Fenders

Keep your fenders clean and free from harmful grit by washing with soap and water. Harsh cleaning agents are not advisable as they will harm the surface of the fender.

Majoni Fender Guide

Fender covers are washable and help to keep your fenders clean and grit free as well as protecting them from the elements.

Shop for Fenders

Anchoring Information