Mooring (watercraft)

A mooring refers to any permanent structure to which a vessel may be secured. Examples include quays, wharfs, jetties, piers, anchor buoys, and mooring buoys. A ship is secured to a mooring to forestall free movement of the ship on the water. An anchor mooring fixes a vessel's position relative to a point on the bottom of a waterway without connecting the vessel to shore. As a verb, mooring refers to the act of attaching a vessel to a mooring.

The term likely stems from the Dutch verb meren (to moor), used in English since the end of the 15th century.

These moorings are used instead of temporary anchors because they have considerably more holding power, cause less damage to the marine environment, and are convenient. They are also occasionally used to hold floating docks in place. There are several kinds of moorings:

Swing moorings also known as simple or single-point moorings, are the simplest and most common kind of mooring. A swing mooring consists of a single anchor at the bottom of a waterway with a rode (a rope, cable, or chain) running to a float on the surface. The float allows a vessel to find the rode and connect to the anchor. These anchors are known as swing moorings because a vessel attached to this kind of mooring swings in a circle when the direction of wind or tide changes.

For a small boat (e.g. 22' / 6.7 m sailing yacht), this might consist of a heavy weight on the seabed, a 12 mm or 14 mm rising chain attached to the "anchor", and a bridle made from 20 mm nylon rope, steel cable, or a 16 mm combination steel wire material. The heavy weight (anchor) should be a dense material. Old rail wagon wheels are used in some places (e.g. Clontarf, Dublin, Ireland) for this purpose. In some harbours (e.g. Dun Laoghaire, Ireland), very heavy chain (e.g. old ship anchor chain) may be placed in a grid pattern on the sea bed to ensure orderly positioning of moorings. Ropes (particularly for marker buoys and messenger lines) should be "non floating" to reduce likelihood of a boat's prop being fouled by one.

Pile moorings are poles driven into the bottom of the waterway with their tops above the water. Vessels then tie mooring lines to two or four piles to fix their position between those piles. Pile moorings are common in New Zealand but rare elsewhere.

While many mooring buoys are privately owned, some are available for public use. For example, on the Great Barrier Reef off the Australian coast, a vast number of public moorings are set out in popular areas where boats can moor. This is to avoid the massive damage that would be caused by many vessels anchoring.

...
Wikipedia