SeaTrac and the University of Southern Mississippi are working together to demonstrate the use of SeaTrac’s SP-48 uncrewed surface vessel as a persistent surface expression for uncrewed underwater vehicles, subsea sensors, and other underwater assets. The demonstration will evaluate how a low-logistics, long-endurance USV can support subsea operations by providing remote positioning, command-and-control support, and communications relay capabilities using an integrated Sonardyne Gyro USBL 5000 system.
Subsea operations increasingly depend on distributed underwater systems, including UUVs, seabed instruments, acoustic modems, and other autonomous or remotely monitored assets. These systems often require a surface node to provide acoustic positioning, data relay, mission coordination, and operator awareness. Traditionally, this role has been filled by crewed vessels, which can introduce significant cost, scheduling, endurance, and personnel-risk constraints. The SP-48 demonstration is intended to show how an uncrewed maritime system can assume many of these surface-support functions while reducing operational burden and enabling more persistent subsea presence.
The SP-48 is a 4.8-meter, solar-powered USV designed for persistent operations from nearshore environments to open ocean. It supports 24/7 operations, redundant communications, man-in/on-the-loop remote supervision, waypoint-based mission execution, AIS, 360-degree situational-awareness cameras, and multiple payload configurations. SeaTrac has previously operated the SP-48 on long-duration missions exceeding two months and 1,600 nautical miles, and has demonstrated acoustic payload operations, including a Gulf of Mexico data-harvest mission using a Sonardyne HPT 7000 payload to collect data from nine seafloor sensors over approximately 570 nautical miles.
For the proposed demonstration, the SP-48 will be configured to act as a mobile and persistent surface node for underwater assets. The system concept includes the Sonardyne Gyro USBL 5000 for acoustic tracking and positioning; onboard communications links to move vehicle, payload, and mission data ashore; and remote supervision from SeaTrac’s operations architecture. The University of Southern Mississippi team will lead test planning, evaluation, and demonstration activities, with SeaTrac supporting platform integration, operations, and mission execution. The work will assess how the integrated system performs as a surface expression for UUVs and other underwater assets, including its ability to support acoustic positioning, relay operational data, maintain mission awareness, and coordinate with shore-based operators.
This presentation will provide an overview of the demonstration objectives, system architecture, planned test approach, and results available at the time of Underwater Intervention 2026. It will discuss the operational value of using uncrewed surface vessels to support subsea work, including reduced dependence on crewed vessels, increased endurance, lower logistics, persistent access to remote operating areas, and the ability to scale support for distributed underwater systems. The presentation will also address practical considerations such as payload integration, remote operations, communications paths, safety and recovery planning, and coordination between USV operators and subsea mission teams.
The broader intent of this effort is to demonstrate that uncrewed maritime systems such as the SP-48 can provide a reliable, cost-effective, and scalable surface-support layer for subsea operations. By combining persistent USV operations with proven acoustic positioning and communications technologies, the demonstration will show a pathway toward more efficient support of UUV missions, subsea infrastructure monitoring, seafloor sensor networks, environmental data collection, and future offshore intervention activities.
