3.5 Docking, Undocking & Line Handling

The Dock Lines and What They Do

Docking is boat handling plus line handling, and it starts with knowing the lines by their jobs. A vessel is normally made fast with as many as six lines:

• Bow line - runs forward from the bow to the dock; stops the bow from drifting aft and away.
• Stern line - runs aft from the stern; stops the stern from drifting forward and away.
• Breast lines - run straight across (athwartships) from bow or stern to the dock; hold the boat close alongside but do nothing to stop fore-and-aft surge.
• Spring lines - run fore-and-aft along the dock and are the workhorses of ship handling. An after bow spring leads aft from the bow to the dock; a forward quarter spring leads forward from the stern. Springs stop the boat surging ahead and astern along the dock, and - crucially - they let you use engine and rudder to pivot the boat on or off the pier.

Springing On and Off

The power of a spring line is that it converts the engine's straight-line thrust into a turning force. Hold the boat by a single spring, apply throttle against it, and the hull pivots about the point where the spring is made fast:

• Springing the stern out - rig an after bow spring, put the engine ahead against it with the rudder turned toward the dock. The boat cannot move forward (the spring holds the bow), so the thrust swings the stern out away from the dock. Once the stern is out, cast off, shift to reverse, and back clear.
• Springing the bow out - rig a forward quarter spring, put the engine astern against it. The stern is held, so the bow swings out; then go ahead and drive off.

Spring lines let a single-screw boat leave a berth even when wind or current pins it hard against the pier - a situation where lines alone, without the engine, would leave you stuck.

Planning the Approach

Before you ever touch the throttle for a landing, read the wind and current and decide which one dominates. The governing principle: when practical, approach into the stronger of wind or current so that it works as a natural brake, slowing the boat and giving you positive control at low speed. Approaching with a fair wind or current behind you removes your brakes and invites a fast, hard-to-stop arrival.

Make the approach at a shallow angle (roughly 10 to 20 degrees to the dock) and at the slowest speed that maintains steerage. Remember the pivot point: as you straighten alongside, the stern swings in, so leave room. When wind or current sets you off the dock, angle in more steeply and be ready to use a spring to stop and pull alongside; when it sets you onto the dock, come in shallow and let it ease you down. Have fenders over at the points of widest contact and lines coiled and ready with handlers briefed in advance on which line goes ashore first (usually a spring or the bow line, to check headway).

Line-Handling Technique

Good line handling is quiet and unhurried. Coil lines for a clean throw or hand-off. When placing an eye over a piling already carrying another boat's eye, dip the eye - pass yours up through the other and over the top - so either boat can leave first. Take a turn on a cleat or bitt before the load comes on, and surge the line (let it slip in a controlled way around the cleat) to absorb a surge rather than trying to hold it dead. Keep hands, fingers, and feet clear of bights and loops that could snap taut; a line under load is dangerous. Communicate with clear, standard commands - "take a strain on the bow spring," "hold the stern" - so every handler acts together.

Mooring to a Float or Piling

Not every landing is a bulkhead. At a floating dock the boat rises and falls with it, so line length is not critical, but you still spring on and off the same way. At pilings, where there is no continuous face, you run lines to individual posts - often a bow line and stern line to outboard pilings and springs led to inboard ones - and adjust for the tidal range so the boat neither hangs on taut lines at low water nor drifts on slack lines at high water. A mooring buoy is picked up by its pendant with a boat hook; approach it slowly, into wind or current, and take the pendant to a bow cleat.

Scenario. A 40-foot charter lies port-side-to a fixed pier with a 15-knot wind pinning her onto it - lines alone will not get her off. You rig an after bow spring from the bow leading aft, set a fender at the bow, and put the engine slow ahead with the rudder hard to port (toward the dock). The spring holds the bow; the thrust walks the stern out into the wind until it clears. You cast off the spring, shift to reverse, and back straight out into open water - the engine and one spring line doing what four dock lines could not.