All boats come with cleats installed, right? And the manufacturer installed them, so they must be right for the job and mounted correctly, right? The answer to both questions is a firm maybe. Some boats hew more to a design ideal than operating conditions, putting form and styling above function. Cleats can be undersized, improperly mounted or just plain missing.

Thankfully, installing cleats is something most boaters with average do-it-yourself skills can learn to do. Follow along and we'll go through Cleats 101, which includes how to select them, mount them, back them, bed them and minimize the mess along the way. As a bonus, most of the techniques discussed here also apply to installing other deck fittings.

Cleats generally come with the deck structure itself, fasteners and a backing plate. All are important to a successful installation, meaning the cleat stays with the boat and holds in the most severe conditions the boat endures. A look through any boating catalog or marine store will turn up a bewildering variety of styles. Some types are for other than deck use, such as galvanized dock cleats, cam cleats and jam cleats used by sailors. For our purposes here, we'll stick with those mounted on the deck and generally used for dock lines.Glen Justice

Most cleats have two horns connected to some sort of base. That base can be open or closed, and the cleat can use two fasteners or four. The cleat itself can be made from stainless steel, bronze or aluminum, but stay away from plastic cleats for dock lines. Some home boat builders have even made their own cleats from teak or similar hard woods.

I prefer the classic Herreshoff cleat for bow installations, and stern installations where there is enough room. The Herreshoff cleat is a four-bolt, open base style. I like the open base so I can pass the eye splice of a dock line through the base and over the horns. At my home dock, I have the bitter ends of my dock lines tied off to the dock cleats and the eye splices for use on the boat. With the dock lines remaining properly adjusted at the dock, it is a simple matter to pick up the eye splice and attach it. Tying off at the dock is quickly done and everything is perfectly adjusted.

Whatever your habit, learn how to properly tie off a dock line around a cleat. Nothing looks worse than walking down the dock and seeing some of the weird knots people use. More turns isn't better, and piling turn after turn doesn't really help.

SIZING YOUR CLEAT

Selecting the right cleat is more than just finding what strikes your fancy. The cleat must be big enough for the line or lines you intend to use. Most boating catalogs will list a maximum size line the cleat will handle. I would suggest going to the next size larger cleat for any given line size. For example, if you use ½-inch dock line, select a cleat designed for 5/8-inch line. This is especially true when using a single bow cleat to secure two bow lines.

Graphic by Paul Esterle Ah, but what size dock line should you use? The folks at West Marine recommend 1/8-inch of line diameter for every 9 feet of boat. A look around any marina will reveal that many people seem to tie up using whatever they have, and that the most common sin is undersized dock lines. The second most common sin is using cheap yellow polypropelene line.

But bigger isn't always better. Bigger lines are stronger and easier on the hands but they stretch less. That stretch helps alleviate the shock loads from passing wakes and surges. So the moral of the story is that you should select the dock line first, and then select the proper size cleat.

Selecting the proper size cleat is only half the battle. For the cleat to serve its purpose, it must be installed correctly. Any discussion about mounting anything on the deck of a boat needs to start with the way most decks are made. Almost every deck built today uses some type of "cored construction," a technique whereby two layers of fiberglass are separated by a layer of core (see illustration).

That core material can by plywood squares, end-grain balsa, plastic foam or a type of honeycomb material. The top and bottom fiberglass skins must be tightly bonded to the core material. The resulting structure is lighter and far stiffer than the fiberglass alone would be.