Consider the fender, that humble tube or globe of lightly inflated vinyl whose noble mission is to prevent dings and scratches to your boat’s hull. At Spinnaker, we mostly use them to separate our boats from the docks, tying them so that they dangle from the lifelines.

A stroll along any marina will show boats with varying shapes, colors, and sizes of fender- many of the tubes vertical with a few horizontal. Some are fully out of the water; others are clearly taking a bath. A few have cloth covers, protecting the protectors. The knots and clips that bind them to the boats vary dramatically.

There is no one “right way” to use or to attach a fender, but some are more practical and useful than others. Here are some tips to consider:

DOCKING

What type of dock are you pulling your boat up to? Spinnaker’s docks are float, which simply means that they move up and down with the tide. That’s a tremendous convenience, for the dock stays at the same level as the boat, even with the tide coming in and out several times per day.

Other docks- especially in parts of the world where the tide is minimal- are fixed. They are firmly attached to pilings dug into the ground or are simply projections from the shore. Moving up the channel from Spinnaker towards the Bay, you’ll see a fixed dock where the ocean-going commercial vessels take on their cargo. On a fixed dock, the distance from the ship’s deck to the mooring bitts on land will change as the tide in the channel ebbs and flows.

Spinnaker uses two types of fenders: cylindrical double-eyes and cylindrical center holes. The double-eyes have a flattened tab with a hole at each end. Usually only one eye has a line attached, allowing the fender to hang vertically. If you want the fender to hang horizontally, you need to attach a second line to the other eye.

Center hole fenders are slightly stiffer and have a hole that passes all the way through its long axis. This allows you to hang it either vertically or horizontally by using only one line that goes through its middle.
Why do we want that vertical/horizontal option? With a floating dock, the boat will only need to be protected from bumping up against the dock’s rub rail. Since it stays at the same level as the fender, the only significant movement is horizontal. It makes sense to place the fenders vertically so that they’ll contact the dock even if the boat rolls a bit from a wake or from a passenger coming aboard.

But if the dock is fixed, you’ll want to set up your lines so that both they and the fenders can compensate for the tidal changes throughout the day. Most of the time you’ll be tying up next to one or more pilings that you’ll have to protect your boat from as it moves up and down.

If you rotate the fenders so that they’re horizontal and supported by two lines, then they’ll be more likely to protect your boat as it rises or falls with the tide, even if it shifts forward or back a bit from a wave or anything else. In fact, some sailors attach the horizontal fenders to the pilings instead of to their boats so that they’re sure they’ll stay in place.

 

Rafting

Rafting is a nautical term for attaching one boat to another when you’re anchored or when one boat is at a dock. It’s a way to socialize with other sailors. This is a good time to use those fenders that look like mooring balls. At the very least, you should use the largest fenders you have on board; each boat should protect itself with multiple fenders on both sides. That’s because different size boats tied together will rock differently and have different amounts of freeboard—the height of the deck above the waterline.

Put the smallest fenders you use near the broadest part of your beam, and the biggest fenders fore and aft.

Tie One On

Sailors have endless debates about the best knot to use when attaching a fender. Many use a clove hitch. It’s fast, sturdy and simple to tie. Its disadvantage is that it’s not easy to adjust the height of the fender once you’ve tied it. Others use a slippery clove hitch, claiming that it also is very fast to untie. (I’ve never run across a situation in which untying a fender was critical, but that may just be me.)

 

I was originally taught to attach fenders using two round turns over the lifeline followed by two half hitches around the standing end of the line—the part attached to the fender. It’s slightly more complex than the clove hitch, but has the advantage of allowing you to adjust the height of the fender easily so that it sits just clear of the water. I’ve recently switched over to using two round turns followed by a tautline hitch, which adds another turn around the standing end of the line. It’s no more secure than what I did before, but I think it looks a little prettier. Ah, vanity!

At Spinnaker we usually tie the fenders to a lifeline when we dock. It’s easy and accessible, and perfectly fine for our marina. But if you’re tying up to a piling, a fixed dock, or joining a raft of boats, it’s not a good idea. In each of these situations, there’s much more movement of and pressure on the fenders. Lifelines aren’t designed to take that stress. Also, the length of the line from the knot to the fender is long, allowing the fender to swing in a large arc. In these situations, it’s better to attach the fender to something stronger and closer to the deck, such as the base of a stanchion or a cleat.

Size Matters

How big should your fenders be? A rule of thumb for tubular fenders is one inch in diameter for every five feet of boat length. Thus a fender on a Merit 25 should be at least five inches in diameter; one on a Catalina 27 should be six inches in diameter. For a ball-style fender, use two inches for every five feet of boat length.

How many should you carry? Think of it this way: It’s rare to find a cruising sailor who complains about having too many available fenders when faced with possible damage to his or her boat.