Welcoming Ships and Nautical Sound Signals: Custom or Rule?

A ship’s horn can mean different things during an encounter at sea. On the Elbe, the Willkomm-Höft facility greets passing ships with a local ceremony. At sea, however, sound signals have defined meanings when given under the International Regulations for Preventing Collisions at Sea (COLREGs) or supplementary German regulations.

Willkomm-Höft: a local welcome

Willkomm-Höft is a welcoming facility on the Elbe near Wedel. The ceremony includes the national anthem of the passing ship, a greeting in its country’s language, and a flag salute. The facility was established in June 1952.

COLREG Rule 34: manoeuvres and doubt

The manoeuvring signals in Rule 34 apply to power-driven vessels underway when they are in sight of one another. One short blast means “I am altering my course to starboard”; two short blasts mean “I am altering my course to port.” Three short blasts mean that the engines are being operated astern. This does not necessarily mean that the vessel is already moving astern through the water: the signal indicates engine operation, not simply the vessel’s actual direction of movement. If there is doubt about the intentions or actions of the other vessel, Rule 34 calls for at least five short, rapid blasts. Overtaking signals also do not apply to every encounter; the special agreement in Rule 9(e) is limited to the narrow channels or fairways described there.

COLREG Rule 35: signals in restricted visibility

Rule 35 applies by day and by night in or near an area of restricted visibility. A power-driven vessel making way through the water sounds one prolonged blast at intervals of no more than two minutes. A power-driven vessel underway with its engines stopped and making no way through the water sounds two prolonged blasts, about two seconds apart, at the same maximum interval. For vessels not under command, vessels restricted in their ability to manoeuvre, vessels constrained by their draught, sailing vessels and fishing vessels, as well as vessels towing or pushing, the rule instead prescribes one prolonged blast followed by two short blasts. What matters, then, is the vessel’s specific situation—not merely that fog is visible. This distinction helps prevent a sound signal governed by the rules from being mistaken for a welcome taking place ashore at the same time.

Additional German signals

Germany’s Maritime Traffic Regulations supplement the COLREGs with certain signals that apply within their jurisdiction. For general danger or warning, Annex II specifies one prolonged blast followed by four short blasts; the sequence is repeated if necessary. The “keep clear signal” consists of one short blast followed by one prolonged blast; it is repeated at least five times per minute, with a two-second pause each time. The regulation links it to particular dangerous situations, such as an accident involving dangerous goods, a related threat, or a risk of explosion. These additional regulations should be read alongside the requirements of the COLREGs, not as a blanket substitute for them.

Distinguishing custom from traffic regulations

The sender, the situation and the applicable rule all matter: the music and greeting at Willkomm-Höft are part of a local welcome. A ship’s short or prolonged blasts, by contrast, may indicate a manoeuvre, doubt, danger or restricted visibility. Without the relevant regulatory context, no reliable conclusion about a vessel’s course or right of way can be drawn from a single blast. For further context, see the articles on the duties of the ship’s crew, draught and navigational clearances, and the ship register and flag state.