Recommended Length of Dock Arms and Spacing Between Them
In general, the width of the dock space should not be less than the boat’s beam (width) plus 30 cm, and for larger boats plus 40 cm (boats over 7 m).
The length of the dock arm should be approximately 70% of the boat’s length, allowing the boat to extend slightly beyond the back of the dock, see illustration below.
Depending on the boat’s design, a slightly narrower dock space may work, as the Y-dock arms typically meet the boat’s hull below the gunwale.
Most boats are widest at the gunwale and taper downwards, but this does not apply to all boats.
The easiest way to determine the correct width is to look at similar boats moored at the dock.
How to Moor Your Boat Between Dock Arms
Moor the boat with tight lines so that the bow is positioned 30–40 cm from the dock.
The boat must be secured so that it cannot be pulled all the way in to the dock.
Use one mooring line from each corner of the boat to the dock arms, keeping the boat centered between the arms.
The bow and stern lines should be properly angled and short, preventing the boat from drifting either toward or away from the dock.
All mooring lines must be equipped with shock absorbers, preferably rubber type, to avoid damage.
Boats and dock arms almost always move out of sync, so to prevent damage:
Lines should not run at a 90-degree angle from the boat or dock arm.
Equip the boat with suitable fenders on both sides to protect the hull.
The boat must not be positioned so tightly that the fenders become pinched between the boat and the dock arm.