Fender Facts
Published: Sunday, October 2, 2022 12:00 pm
By: Dan Armitage
A version of this article appeared in the Fall (September/October) 2022 of Great Lakes Scuttlebutt magazine.
When putting your boat to bed for the winter, if you notice some dents along the rub-rail, skid marks, spider cracks, scratches or chips in the hull’s gelcoat, and other signs of impact from boats and docks, you may need to upgrade your fenders over the off-season. That can be as simple as adding a pair to boost your boat’s bump-adsorbing capabilities, upsizing your present collection, selecting a different type of fender altogether, or having on a hand combination of fender types to keep damaging impacts at bay depending on conditions.
Fenders are constructed of materials ranging from heavy-duty vinyl, PVC, rubber, and foam in a variety of shapes and sizes. By far, the most popular fenders among Great Lakes boaters are made of PVC and are cylindrical in shape, aptly referred to as “cylinder” fenders. They come in sizes from 2”x10” to 2’x5’ for recreational craft and are the most versatile of the three most common fender types. Cylinder fenders can be hung vertically from a loop at one end or horizontally by feeding the fender line through loops at both ends. Larger cylinder fenders have a hole through the center to allow a fender line to be threaded through the device. Deploying your fender horizontally is especially recommended while docking in tidal waters, where water levels -- and the boat’s position along the pilings – change as the fender rolls with the flow. Vertical deployment is usually the best choice when pulling into a fuel dock, freshwater boat slip, or when rafting off other watercraft.
When determining the proper size of cylinder fenders for protecting your boat, a common recommendation calls for one inch of diameter for every four feet of boat length. So a 20-foot boat would call for fenders of at least five inches in diameter. That said, bigger is better when it comes between your hull and that battered boat dock, so consider the largest cylinder fenders you can easily stow.
The same is true for “ball” fenders, so-named because of their round shape. Ball fenders are popular among owners of larger watercraft because they can absorb a lot of impact – when properly inflated – and, with their large diameter, can protect hulls that carry lots of bow flare. The downside is that, when inflated, ball fenders take up lots of stowage space aboard when they are not deployed.
Ball fenders come in sizes from 10 to 36 inches in diameter for recreational boats. When selecting a set of ball fenders for a particular vessel, two inches of diameter for every four feet of boat length is a common equation. So a 32-foot boat would need ball fenders of at least 16 inches in diameter. And, as with cylinder models, bigger is better when it comes to ball fenders.
Of the three most popular fender types, these first two discussed here are made of PVC and are hollow and air-tight to allow them to be pre-inflated or custom-inflated to the proper pressure for the circumstances.
The third common style of the fender is made of closed cell foam molded in various shapes to conform to various styles of rub-rails and gunwales. Some are designed for use with personal watercraft, others for rafting-up, and several types specifically intended to protect pontoon boats. Many of these types of fenders don’t require traditional fender lines and are contoured to conform to the shape of the boat in the position where they are deployed, with integrated, adjustable straps used to secure them in place.
Traditional fenders are designed to be tied to cleats or other secure hardware along the perimeter of the boat. If bumpy conditions warrant, it’s important that the fender line be attached to cleats or designated fender attachment hardware. In calm conditions, tying off to a handrail, bow rail, or Bimini bow is acceptable when deploying “boat bumpers.” There are even fender models that use suction cups to attach to the boat’s hull.
No matter what type of fender you use to protect your boat, be sure to remember to stow them aboard when no longer needed. Not only do flying fenders along the gunwale identify a novice boater underway, but the bouncing devices can be lost – along with it, the ability to protect that boat back at the dock.
tags: Boat 101
