Confidential Human Factors
Incident Reporting Programme
The Charity
Aviation
Maritime
M2590
Initial Report
While departing from a fuelling jetty within a harbour, a USV and its support vessel were surrounded by a large number of sailing vessels entering the harbour. Due to the high density of traffic, both vessels were unable to manoeuvre safely, resulting in a near miss. The situation posed a significant risk to life and property, as several vessels were at risk of collision or damage.
CHIRP Comment
This near miss highlights the challenges of operating uncrewed surface vessels (USVs) in busy ports alongside conventional craft. Even well-planned operations can create risk when there is limited room to manoeuvre and many other vessels are present.
All vessels, whether crewed or uncrewed, must comply fully with the COLREGs. USVs are to be treated the same as any other craft, and other water users have an equal responsibility to maintain lookout and take early, effective action to avoid collision (Rules 2, 5 and 6). Likewise, USV operators must comply with Rules 8(e) and 8(f), as well as all other applicable regulations.
The master and remote operator of a USV must be formally nominated and are usually ashore. On small vessels, one person may hold both roles, but a remote operator can control only one vessel at a time, while a master may have several under command.
Seafarers should anticipate congested areas and maintain heightened awareness, particularly during arrival and departure. Port operators and vessel managers should ensure clear traffic management and communication plans are in place whenever USVs are active.
Port authorities may wish to review local regulations and consider guidance for USV operations in areas of dense leisure or commercial traffic, including requirements for signalling, monitoring, and coordination with port control.
Key Issues relating to this report
Situational Awareness – The traffic density overwhelmed the USV/support team’s ability to maintain a clear mental picture of all contacts and their intentions.
Communications – With multiple vessels, tight spacing, and perhaps different operators (yachts, marina control), miscommunication or ambiguity in intentions could lead to misunderstandings.
Complacency – Because departures are routine, operators may have underestimated collision risk, assuming that vessels would “give way” or that traffic would self-resolve.
Local practices – In some ports, it is common practice to depart into busy traffic without clear sequencing or control. This local habit can reduce safety margins and increase the risk of incidents.
Â
Key Takeaways
Regulators and Authorities: Regulate for future vessel types , not just the existing ones.
Mixed crewed and uncrewed vessel operations demand updated procedures and oversight. Integrating USVs into port and VTS systems, strengthening coordination requirements, and refining training and guidance are essential steps to manage future traffic safely.
Managers and Operators: Plan for the crowd — not for the calm.
The event underlines the need for realistic risk assessment and pre-departure coordination that reflect actual traffic conditions, not just the operational plan. Human oversight remains vital, and effective workload management between USV control teams and support craft is key. Safety should never be compromised by schedule or commercial pressure.
Seafarers: If the picture isn’t clear, don’t move.
This incident highlights the importance of maintaining situational awareness when operating in congested waters and recognising that uncrewed systems may have limitations in perception and manoeuvrability. Clear, early communication remains essential, and it is always safer to delay departure than to risk escalation in confusion or congestion.