How to use Boat Fenders and Buoys

Four different sized buoy fenders on the side of a white boat in the water © Boat Accessories Australia

You made a significant investment buying your boat so of course you want to protect it. As careful as you are docking or anchoring your boat, difficult conditions and other boats could damage your hull. There may also be times when you need to leave your boat in the water. Using fenders and buoys can give you peace of mind that your hull will be protected from expensive damage.

What are Fenders?

Fenders act as a cushion to protect boats from damage against docks and other boats moored nearby. Different vessel lengths and weights require fenders of different shapes and sizes. Fenders are made from a variety of materials. Most commonly, they are inflatable and made from PVC or marine-grade vinyl.

The most popular fender for recreational boats is the double-eye cylinder which you can mount either vertically or horizontally using rope strung between the eyes at each end.

The ribbing on some fenders provides reinforcement and minimises the fender rolling. When buying a fender look for in-built UV protection so it doesn't discolour or deteriorate too quickly. The marine-grade vinyl should be soft enough that it doesn't scratch the gel coat on the boat's hull. Some fenders and buoys also have an anti-microbial agent in them to stop some bacteria that causes degeneration of the material.

Choosing the Right Fender

Lots of boaties ask us "What size boat fenders do I need?" The factors to consider when choosing the right fender and number are your boat's length, the weight of the boat and the mooring conditions. A cylindrical fender should have 1" of diameter for every 4 to 5 feet of boat length and 2" of diameter if it's a round buoy. There should be one fender for every 10 feet of waterline and a minimum of three fenders for each side of the boat. If your boat is heavier than normal for its length, or if the mooring conditions are harsh use more fenders than recommended.

Cylindrical fenders are the most common type. The width and length of cylinder fenders increases with the size of the boat they protect. The popular Majoni brand has eight sizes of their popular white and blue top fenders.

How to Tie a Boat Fender

With an eye at one or both ends, you attach the fenders to the side of the boat with a lanyard held in place by a half-hitch or figure 8 stopper knot. Fender rope should be marine-grade nylon dock line that's easy to handle, so it doesn't damage your hands, the fender or the boat's hull surface. Unlike rope, the lanyard should have good elasticity and be resistant to abrasion.

On a boat requiring three fenders, place one fender in the middle of the boat and then a fender fore and aft. Rafting (lashing) two boats together requires more fenders as both boats are moving unlike a stationary dock. Use round fenders fore and aft to protect the bow and stern.

If a fender isn't placed at the correct height, it may not offer your boat any protection. Hang the fender so the bottom just skims the water's surface then the dock can't push the fender up so high that the protection is lost. Only hang fenders from permanent fixtures on the boat such as cleats rather than from movable parts such as lifelines, as they aren't designed to carry that load.

Have two different fenders available to suit all mooring conditions and situations. If you tie up to another boat or dock, don't risk expensive hull repairs because you skimped on fenders. Check the size of the fenders you buy will be adequate to do the job.

What Do Buoys Do?

Buoys are like fenders, just round rather than cylindrical in shape. They are used on powerboats with flared bows and commercial fishing boats where there is a large distance to the dock a fender can't cover. Buoys are ideal for raft-ups because they offer more protection than cylindrical fenders to keep the boats' hulls safe from damage. You can also use buoys in the water as net floats and marker buoys.

Round fender buoys come in several sizes but most recreational boats will choose buoys that are between 9 and 19 inches in diameter. Buoys are available in PVC but double-thickness fabric covers are available in UV and salt-resistant acrylic materials.

Sailboats, ski boats and commercial boats are more likely to use a round buoy rather than a cylinder fender because their hulls are better protected by the round shape.

Storage and Maintenance of Fenders

Leaving fenders in the bottom of the boat while you travel or fish is an annoying trip hazard. Spend two minutes putting the fenders away so you know where they are when it's time to dock.

When not in use, it's best to have a dry place to stow them such as under a boat seat, in a storage locker or in a fender basket system. You can mount the baskets on horizontal, vertical or inclined rails to fit any available position. Clamps can be used to hold multiple baskets together if you need to carry a lot of fenders.

If your fenders are dirty, hose them off or use a fender cleaner/protector to remove grime, scuff marks and oxidation stains.

We recommend a fender bike pump adapter for inflating fenders. The ideal inflation pressure is 0.2 bar. Depending on the brand of fender you buy, it may be worth getting a replacement brass valve. Good quality fenders have a long life of around 40 years if you look after them properly.

Other Fenders and Buoys

Fenders are also available in multi-use cushioned patterns to wrap around edges or to cover steel beams and poles, anything your boat may come in contact with. The arc fender can also be used as a step ladder to board a boat from a dinghy or a dock. Held in place with rope either side, the fender works as both a ladder and fender. Cylinder fenders with a centre hole provide more options for mounting as one rope can slip down the middle and tie at the end, rather than needing two pieces of rope to tie to the two eyes of a standard cylinder fender.

The stern of a boat is particularly vulnerable from damage. A universal fender with a 70 to 90 degree opening fits the stern of most yachts and cruisers to protect it from high shock.

Racing and cruising yachts can protect their bow with a bow fender. This fender suits a maximum bow shape width of 70 mm and is held in place with rope lines (the lines are included with this fender).

The corners of docks, pontoons, marinas and wharfs are dangerous for boats pulling into dock. A corner dock fender can be permanently mounted or used temporarily to keep the boat safe as it bends in two points. A dock edge corner fender can be attached to metal or wooden docks and can sit alongside the straight dock edge fender to provide protection the length of the dock. A heavy-duty dock wheel fender is also for mounting on dock corners to protect boat hulls, and is supplied with a metal mounting bracket.

If you have any queries about the right fender or buoy for your boat, call Boat Accessories Australia on 1300 308 161 or contact us online.