Guard vessels play an important role in ensuring the safety of designated areas and preventing other vessels from approaching facilities or activities requiring additional protection.
Germany’s Federal Bureau of Maritime Casualty Investigation (BSU) has published the findings of an investigation into a less serious marine incident involving a guard tug and a sailing yacht. The case showed that the very attempt to secure an area can create an additional risk if the role of the guard vessel remains unclear, communication is established too late, and the chosen approach leaves little room for an unexpected manoeuvre.
At the same time, the investigation underscored a broader collision-prevention principle: a vessel cannot assume that other traffic participants understand its intentions simply because they are obvious to its crew.
The tug was performing routine support duties while also monitoring a security zone established around two tankers anchored in the roadstead. A sailing yacht subsequently entered the zone. The tug headed towards the yacht to warn its crew and ensure compliance with the minimum separation distance.
The manoeuvres that followed resulted in a collision between the two vessels. The yacht sustained minor hull damage, while the tug was undamaged. According to the investigation materials, the yacht’s crew expressed concern about the tug’s manoeuvring because they did not expect it to approach in that manner.
The BSU identified several factors that contributed to the incident. The tug’s role as a guard vessel was not sufficiently obvious to other traffic participants, so it may initially have been perceived as an ordinary self-propelled vessel. At the same time, the chosen approach created a developing risk of collision.
The investigation also found that the vessels’ intentions were not communicated in good time, and that the yacht’s crew did not have all the information about the local and temporary traffic restrictions in force in the area.
The main problem was that the crews of the two vessels understood what was happening differently.
From the tug’s perspective, approaching the yacht was part of its duties as a guard vessel: the yacht had entered an area it was responsible for protecting and had to be warned. To the yacht’s crew, the tug’s approach was unexpected. Without a clear indication of the tug’s special function and a timely exchange of information, it was difficult to interpret its manoeuvre as a safety-related action.
This distinction is of fundamental importance. A guard vessel may be carrying out a specific operational task, but other vessels are still required to assess the situation based on what they actually observe and understand. The existence of a special duty does not by itself communicate the vessel’s intentions to the crew of another vessel.
The chosen manoeuvre also reduced the time available to both crews to react. A guard vessel attempting to establish contact with another vessel must take into account both the need to intervene and the risk created by reducing the distance. A high closing speed, a small passing distance or an intercepting course can quickly turn a warning manoeuvre into a situation of excessive proximity.
Communication was another missing safeguard. The investigation findings emphasise the importance of establishing contact before the guard vessel comes close, rather than after the situation has become critical. VHF communication can be useful, but should not be regarded as the sole safety measure: recreational vessels may not be equipped with VHF or AIS, and failure to receive a response to a call does not justify further reducing the distance.
GLOAPM.COM