Confidential Human Factors
Incident Reporting Programme
The Charity
Aviation
Maritime
M2615
Initial Report
An uncrewed surface vessel (USV) was operating near a wind farm when it was involved in a collision with a Crew Transfer vessel (CTV). The CTV was reportedly steaming into the bright sun’s reflection and did not see the low-lying USV.
The USV sank immediately. The CTV was damaged but managed to reach a nearby port, where the authorities met the master. It later sailed to another port to undertake significant repairs. The collision was recorded with the authorities.
CHIRP Comment
USVs are still in the early stages of operational maturity, yet their adoption is accelerating rapidly. This pace of change presents evolving risks that regulatory bodies must address proactively. At the same time, managers and seafarers must stay informed of technological developments and remain alert to procedural changes.
This report highlights a key challenge in small vessel operations: maintaining effective lookout and situational awareness under strong sunlight and reflective sea conditions. Bright sun glare on the water can significantly impair visibility and reduce contrast, making it difficult to detect small or low-profile vessels. Risk assessments should account for these environmental limitations and incorporate enhanced lookout protocols or electronic detection aids when navigating into glare. Regardless of vessel type, all operators are obligated to maintain a proper lookout under the COLREGs.
Like crewed vessels, USVs are required to transmit their position and status via AIS. In this incident, CHIRP raised concerns about whether the CTV was conducting an effective radar and AIS watch in addition to visual monitoring. Given the intense glare, reliance on visual detection alone was insufficient. In such conditions, reducing speed (as per Rule 6 of the COLREGs) is essential to allow adequate time for response upon target detection.
Although COLREGs equally binds all vessels, the presence of USVs in wind farm areas should be clearly communicated until their operations become routine. While environmental factors were likely the primary contributors to the incident, human and organisational elements also played a role. The bridge team appeared to rely predominantly on visual watchkeeping, with limited integration of radar and other detection systems.
Routine checks for USV activity in offshore zones are vital for safe navigation. Familiarity with the operating area and the time pressures of offshore transfer operations may lead to underestimating the risks posed by emerging hazards. As USV usage expands globally, a comprehensive review of lookout practices, detection capabilities, and operational procedures will be critical to mitigating collision risks.
Key Issues relating to this report
Situational Awareness – The primary causal factor – the bridge team did not detect the small craft ahead due to glare, indicating loss of situational awareness and inadequate cross-checking with instruments.
Alerting – The small, low-lying vessel was challenging to see and may have been inconspicuous on radar and by visual observation, limiting the CTV crew’s ability to detect it.
 Complacency – Routine familiarity with the operating area may have led to reduced alertness and failure to anticipate the hazard posed by glare or small targets.
Pressure – Offshore support operations are typically time-pressured. Schedule or performance demands may have limited the opportunity to adjust course or speed for visibility conditions.
Key Takeaways
Regulators: Connected vessels are safer.
Consider mandatory tracking or notification systems for USVs and update operational guidelines near offshore structures. Collect and share safety data from incidents to reduce future risk.
Managers: Plan for the invisible before it becomes inevitable.
Risk assessments should account for uncrewed vessel operations, and crews must be trained in detection and collision avoidance. Prompt incident reporting helps capture lessons to prevent recurrence.
Seafarers: If you can’t see it, it might still be in your path.
 Low-profile vessels like USVs can be hard to see, particularly in sun glare. Maintain vigilant lookouts and use all available aids, including radar and AIS. Be ready to respond immediately if a collision occurs.