The utilization of Unmanned Surface Vessels (USVs) has been a transformative force within the survey industry, particularly in shallow water environments, owing to their lightweight design and low draft capabilities. This distinctive feature empowers these vessels to navigate and execute tasks in areas where conventional vessels struggle to operate effectively.

In a recent European project, an USV undertook a pipeline survey across a 12 km nearshore section, facilitating measurements of cathodic potential, field gradient, and burial depth for a 36” pipeline situated in exceedingly shallow waters. The fluctuating water depths ranging from 0.6 m to 3.0 m along the nearshore segment had previously obstructed vessels from collecting CP and Depth of Burial data since the pipeline’s installation over two decades ago. The simultaneous acquisition of a comprehensive suite of survey sensors during a single pass was imperative to ensure timely completion of the project’s scope. A bespoke arrangement integrated three sensors onto the USV, including the TSS HydroPACT 660E Subsea Cable Tracking System, Norbit Winghead Multibeam Echo Sounder, and FIGS Cathodic Protection (CP) system.

This amalgamation, a pioneering attempt at such a configuration, underwent a week-long process encompassing raft design, engineering, and rigorous testing. On-site mobilization was achieved within two hours. The adaptable architecture and hull of the USV facilitated the installation of all three sensors, enabling simultaneous data acquisition during a single-pass mission. This methodology not only simplifies data collection complexities but also minimizes environmental impact due to its low noise and disturbance levels.

Unique Group’s presentation will provide a comprehensive overview of the economic, safety, and operational advantages derived from employing USVs for shallow water pipeline surveys, emphasizing the tailored sensor configurations on USVs aligned with specific application requirements.


David Rennie

David Rennie, Technical Manager at Unique Group’s Autonomous division, oversees the management of the company’s USV fleet (Uni-Mini, Uni-Pact, and Uni-Max) and Exail’s iXblue for global projects. With a background in electrical and electronic engineering from Edinburgh University, David’s expertise includes scoping, commissioning and managing marine geophysical surveys for the Oil & Gas, Renewables and Construction

He has a robust track record, having worked at GSE Rentals for 16 years before transitioning to roles at Fugro Survey and Senergy Survey and GeoEngineering (now Lloyd’s Register S&G. David, based in Aberdeenshire, Scotland, is a proud member of the Institution of Engineering and Technology (IET).