The US National Transportation Safety Board (NTSB) issued six safety recommendations on Tuesday, October 27, following its investigation into a 2024 Lake Erie collision involving a recreational vessel and an uncrewed surface vessel (USV) used for research.
The collision occurred on August 10, 2024, six statute miles (9.7 kilometres) east-southeast of Monroe, Michigan. A 45-foot (13.7-metre) motor yacht travelling at about 25 mph (40 km/h) struck a SeaTrac SP-48 USV operated by the National Oceanic and Atmospheric Administration (NOAA) Great Lakes Environmental Research Laboratory (GLERL). The recreational vessel's operator sustained a minor foot injury.
The USV was a constructive total loss valued at $186,000. Damage to the recreational vessel was estimated at $100,000.
The NTSB determined that the probable cause was the USV's inadequate detectability in the prevailing conditions, combined with insufficient active monitoring for its operating mode and actual autonomy, which left it without a proper lookout.
The 15.7-foot (4.8-metre) craft had about one foot (0.3 metres) of freeboard and no radar reflector, and its cameras were switched off. GLERL staff learned of the collision only when the coast guard called more than 30 minutes after impact.
"As USVs become more commonplace in US waterways, it is critical for the coast guard to begin to set standards and policies for these vessels," the board stated.
It recommended that the US Coast Guard develop national perceptibility, collision avoidance and navigational safety standards for USVs and incorporate them into regulations.
NOAA was asked to require detectability testing and monitoring commensurate with each USV's actual autonomy. SeaTrac Systems was asked to modify the SP-48 design to improve its perceptibility.