Anchorage (maritime) — place where a vessel is anchored

Characteristics and considerations

Good anchorages share several practical qualities. Mariners evaluate depth, seabed type (sand, mud, rock), shelter from prevailing winds and waves, and the space required for a vessel’s swinging circle as wind or tide changes direction. Other important factors include proximity to channels, traffic separation schemes, and the presence of underwater hazards.

• Holding ground: the ability of the seabed to hold an anchor.
• Depth and tidal range: must allow safe anchor scope and avoid contact with the bottom at low tide.
• Shelter: protection from wind and swell to reduce strain on anchor gear.
• Swinging room: clearance so vessels on anchor do not collide.

History and development

Natural anchorages have served seafaring peoples for millennia as places to shelter, load and unload goods, or wait for favorable conditions. With modern navigation and port regulation, authorities often define fixed anchorage areas to manage traffic, minimize environmental risk, and coordinate pilotage. These areas are published on charts and in port notices.

Uses and examples

Vessels use anchorages for a range of reasons: awaiting a berth, taking shelter in bad weather, conducting ship-to-ship transfers, or complying with quarantine or inspection requirements. Designated anchorage grounds are frequently controlled by port authorities, and vessels may need permission or to follow specific procedures when using them. For official information consult nautical charts and port notices such as nautical charts and port notices.

Regulation, safety and distinctions

Anchorage areas are subject to local and international rules concerning navigation, pollution, and safety. Dragging anchor is a common hazard that can cause collisions or groundings; therefore, watchkeeping, anchor alarms and appropriate anchoring technique are essential. Distinctions: an anchorage is different from a harbour or berth, and from mooring buoys which provide fixed attachment points rather than free-lying anchors.

Finally, the term "Anchorage" is also widely known as a place name (for example, the city of Anchorage in Alaska), illustrating how maritime features often lend their names to settlements formed around safe anchorages.