Dock lines should be made of 3/8” or ½” nylon. Nylon is used because it stretches, providing some protection against the shock loading (strain) on boat fittings caused by wind, currents, or waves caused by the wake of other boats pushing against the boat. Nylon also has the advantage of being less affected by rot or weakening due to exposure to sunlight. NEVER use cotton or polypropylene for dock lines!

A minimum of four ties will keep your boat secure to the dock in all weather conditions. These
four lines are:

1. The Bow Line; 2. The Stern Line; 3. The Bow Spring Line and 4. The Stern Spring Line.

The bow and stern lines hold the boat up against the dock and the spring lines keep the boat from moving in and out of the berth and possibly striking the bow against the dock. With adequately strong Nylon lines tied to well mounted deck and dock cleats, these are the only lines you will need for safe mooring. If your boat has fairleads (metal rope guides), run the lines through them but keep in mind that these are also chafe points.

FENDERS

Fenders keep the hull of your boat from rubbing against the wood and metal of the dock.
Fiberglass boat hulls can wear completely through an unprotected area in a matter of hours in
high wind and wave conditions. Use at least two, preferably three, adequate sized fenders on the side of your boat against the dock. Fenders can be tied to cleats, railings or awning frame, but never to another rope and should hang with the bottom at least 3” in the water. Check all fenders, particularly inflatable ones, to insure that they hold air under pressure over a period of time.

CLEATS

Make sure that your boat has adequate cleats for safe mooring. Most trailerable boats have two stern cleats and one bow cleat that are too small for high wind berthing and for tying more than one line. This makes it difficult to use spring lines. A prudent owner will remove the old cleats and install new, oversized cleats at these locations and then install the removed old cleats on the deck edges about 1/3 of the way back from the bow (see illustration above), so that the stern spring line will not rub against the deck, giving a total of 5 secure cleats for the boat. Stainless steel cleats, backing plates, nuts and bolts are recommended.

HOW TO TIE OFF

Pull boat and fenders against dock with a loop under the cleat as shown in figure 1. Tie your line to the cleat using at least two complete figure 8 loops as shown in figure 2. Follow with two figure 8 locking hitches as shown in figure 3. Run extra dock line back to the boat to prevent tripping. If your dock line has an eye at one end, use this end on the boat cleat. If your line does not have an eye, tie an eye loop using a bowline knot. Make the loop slightly bigger than the cleat. Do not use figure 8 ties on boat cleats, they are too small to put a safe number of turns on.

CHAFING

Winds and currents keep boats straining and moving against their lines. That action leads
to chafing. Where a dock line touches a part of the boat or dock, there will be rubbing (chafing)
on the line. If the line wears completely through at a chafe point, this is a dangerous situation.
Use chafing protection in the form of lengths of old garden hose or canvas fire hose slid over
the rope and kept in place with nylon tie straps, or hose clamps, and laying over the chafe
point.