Underwater sound is central to understanding and managing ocean environments. Whether for measuring the impacts of pile-driving during offshore construction, identifying the presence of marine mammals, or detecting unauthorized vessel activity, acoustic data offers critical insights. Historically, gathering that data has required custom moorings, large power budgets, periodic site visits for data retrieval, and complex post-processing. These constraints have limited the scale and frequency of acoustic monitoring, especially in remote or dynamic marine environments.
To address these challenges, Sofar Ocean has added Applied Ocean Science’s (AOS) BOREALIS hydrophone to the Spotter Platform, creating a compact, intelligent, and fully solar-powered solution for real-time underwater sound monitoring. BOREALIS features low self-noise, omnidirectional response, and a configurable sampling range up to 62.5 kHz, enabling detection of a wide range of acoustic signals. When paired with the Spotter buoy, a rugged, solar-powered surface platform with satellite and cellular connectivity, the system becomes fully autonomous. BOREALIS connects to Spotter via the Bristlemouth open interface standard, enabling plug-and-play integration and remote reconfiguration. This modular architecture simplifies deployment logistics while making it possible to scale monitoring efforts across multiple sites or projects.
What distinguishes this system from conventional hydrophone configurations is its ability to host ML models and process acoustic data at the edge. Each BOREALIS comes with 2 on-board processors; the first allows aggregated signal processing for metrics like Sound Pressure Level (SPL) and Sound Exposure Level (SEL) to be calculated on-board and sent in real-time without incurring the overhead of transmitting entire WAV files. The second processor can host user defined dedicated ML models or applications for detecting and classifying various biological and anthropogenic signals. These dual edge processors revolutionize how users interact with acoustic data, being able to set aggregated threshold-based triggers, send real time alerts for detection events and perform remote sensor fusion with other connected Bristlemouth sensors. All system parameters can be adjusted remotely via the Spotter Dashboard or API, minimizing the need for field intervention.
The system supports multiple operational modes: continuous, duty-cycled, or event-based, allowing users to balance data fidelity with endurance. Data access is streamlined: full spectrograms are stored onboard, waveform data can be retrieved from the hydrophone SD card, and high-level metrics are transmitted in real time.
This presentation will introduce the integrated system’s architecture, data outputs, and early findings from real deployments. It is intended for offshore operators, underwater construction professionals, researchers, defense contractors, and any stakeholders seeking scalable tools to monitor and respond to underwater sound in real time.
