Reviewed by Lexie CornerApr 18 2025
A recent study by ProtectedSeas researchers demonstrates the potential of marine radar technology to monitor the speed of small vessels. The study, which aimed to test the accuracy of radar in detecting potential infractions, found that the device could detect speed violations with 95 % confidence. This suggests that marine radar could be a viable tool to help reduce the risk of vessel strikes on whale populations.
The impact of small vessels on whales is becoming an increasing concern in busy maritime areas, as the number of recreational and commercial boats in these regions rises. A 2020 study led by the ProtectedSeas team found that smaller vessels can make up 34 % of traffic in congested ports such as San Francisco Bay.
Unlike large commercial vessels, which are often monitored using the Automatic Identification System (AIS), smaller boats often go undetected, making it harder to enforce speed limits and prevent strikes, particularly in areas where whales are migrating and feeding.
Radar is a widely available tool that is accessible to a large audience, such as enforcement agencies, marine resource managers, and researchers. The accuracy values from our study can be used to confidently enforce speed limits using radar.
Samantha King, Study Lead Author and Senior Scientist, ProtectedSeas Marine Monitor (M2)
The researchers conducted a large-scale study comparing radar and AIS data from the M2 system across 3,097 vessel tracks at ten locations to assess the accuracy of radar-reported vessel speeds.
The study found a strong correlation between radar and AIS speeds, with vessels traveling within 1.8 knots of radar-reported speeds and AIS values at a 95% confidence level. Understanding radar speed accuracy improves the reliability of reporting and analysis, which is essential for the design, monitoring, and enforcement of vessel speed limits.
According to the researchers, radar technologies like M2 can effectively track speed limits to help reduce vessel collisions with endangered whales, particularly in areas such as the North Atlantic right whale seasonal management zones along the US East Coast, where fewer than 370 individuals remain.
This study confirms that marine radar, similar to road speed monitors, can be used to track the speeds of smaller vessels that are not equipped with AIS. Marine radar technology can be an effective tool to monitor and enforce speed limits for smaller vessels to better protect whale populations.
Brendan Tougher, Study Co-Author and Co-Founder, Marine Monitor (M2)
Journal Reference:
King, S. C., et al. (2025). Estimating Speed Error of Commercial Radar Tracking to Inform Whale–Ship Strike Mitigation Efforts. Sensors. doi.org/10.3390/s25061676