Docking lines for small yachts

Drop Zone

Does a six or seven-metre cruising yacht need the same number of docking lines as a 20m cruiser? If not, how many lines does the small cruiser need? Ralph Chant explains the method he uses with success on his trailer-sailer, Splash.

In good weather you will find many trailer-sailers using two lines: a bow line and a stern line. Most will have a couple of fenders between the boat and the dock. This works well enough until the sea state gets up, or until a large, wake-producing vessel sweeps majestically past the dock. In those circumstances the shortfalls of the two-line method become obvious. The main failing will be the inability of two lines to maximise the effectiveness of any fenders that are deployed.

In a wide range of locations, Splash has done very well on four mooring lines with a minimum of two fenders. The elements to be considered when docking are your boat, the dock, your docking lines and your boat’s fenders.

Boat and dock

Ensure the docking cleats/bollards on your boat can withstand extreme loads and shock loading, eg if deck-mounted, they should have substantial backing plates under the deck.

Always have a good look at the condition of any dock bollards, dock poles etc that you are going to use. Look to where those items are fixed to the dock and check the condition of those fixtures.

Docking lines

This method recommends using four docking lines. When using a fixed dock (where the height between your boat and the dock will change with the tide) you will need to know the range of the tide. The range of the tide is the height difference between the water levels at high tide and low tide.

Initially your bow and stern lines should be about three times the range of the tide. The spring lines should be twice the range of the tide. Attach the bow line (line 1 in the diagrams) to the bow of your boat or to a point near the bow but outboard of the boat’s axis if possible. Tie the other end of the bow line to the dock at a point forward of the bow of your boat. Attach a spring line (line two in the diagrams) to a point well behind your boat’s midpoint. Tie the other end of that spring line to the dock at a point forward of your boat’s midpoint. Attach a spring line (line three in the diagrams) to a point well forward of your boat’s midpoint. Tie the other end of this spring line to the dock at a point behind your boat’s midpoint. Attach the stern line (line 4 in the diagrams) to the stern of your boat; outboard of the boat’s axis if possible. Tie the other end of the stern line to the dock at a point behind the stern of your boat.

Fenders

The number of fenders required will depend on the shape of your boat and the physical features of the dock and is not affected by the range of the tide. When setting your boat’s fenders make sure they line up with an appropriate bit of the dock.

After you have tied up, at the first low tide you will need to check and adjust your lines and fenders. At low tide, in fair conditions, your lines must not be tight but should be taken up to a point where they have some slackness remaining in the line. The amount of slack should be enough to allow your boat to respond to the prevailing wave conditions without straining any of the lines. Use these “low tide” adjustments when docked at a floating jetty or in an area where there is no discernible or significant tide range.