Sessions

Project SeabAId, jointly led by ENSTA and Shom, aims at automatically inferring the nature of the seafloor using a supervised deep learning approach. Using a large dataset of EM710 MKII data and seabed nature maps produced experts, we train a U-net model to perform the segmentation. Depth and seabed backscatter data are used for training and validation in two kinds of representations: geographical map representations or ping/beam representations. Prediction results from each type of input are compared and discussed.

Co-authors:

Hugues Moreau, Gilles Le Chenadec and Sabrina Homrani (ENSTA, Lab-STICC UMR CNRS 6285)

Christophe Vrignaud and Elodie Marches (Service Hydrographique et Océanographique de la Marine)

Decades of ocean-mapping surveys have produced extensive 12 kHz multibeam echosounder data that include backscatter intensity useful for estimating seafloor sediment types and geoacoustic properties. This work catalogs NOAA’s 12 kHz MBES holdings to identify, quantify, and map intersecting survey transects that can support harmonization across platforms. A relative calibration method is applied to align datasets to a common reference system, enabling more consistent backscatter analysis and subsequent sediment-type classification across historical ocean mapping surveys.

A long-standing concern for seabed infrastructure is the mobility of the substrate. A prime issue is seabed scour in shallow seas impacted by either tidal or wave-driven currents. To understand the scale of sediment transport requires simultaneous monitoring of the time-varying 3D current field, water mass boundaries, suspended sediment and the associated changes in the seabed. This presentation will illustrate balancing interference and data density using simultaneous multiple EM systems, a CP-300 ADCP and K-Sync.

Multibeam water column data enable investigating targets above the seafloor. A notable application is detecting underwater gas bubble  release. Recent research shows that water column data can further  quantify detected gas flow rates, enabling operationally efficient  assessments of leakage impact and priority. We present MBES-based quantification using EM710 measurements from Black Sea natural seeps and EM2040 measurements from a synthetic bubble source in the North Sea. We highlight methodological strengths, limitations and acoustic calibration challenges.

Co-authors:

Geert de Bruin (TNO Geological Survey of the Netherlands and NIOZ The Royal Netherlands Institute for Sea Research )

Laurens van der Marel (TNO Geological Survey of the Netherlands and Utrecht University, The Netherlands)

Nore Praet (Flanders Marine Institute (VLIZ))

Thomas Vandorpe (Flanders Marine Institute (VLIZ))

Mario Veloso (Develogic GmbH)

Mehdy Ghasemzadeh Diva (NIOZ The Royal Netherlands Institute for Sea Research)

Jens Greinert (GEOMAR Helmholtz Centre for Ocean Research Kiel)

Gert-Jan Reichart (NIOZ The Royal Netherlands Institute for Sea Research and Utrecht University, The Netherlands)

Thomas Hermans (Ghent University, Department of Geology)

Sciara del Fuoco (SdF) is the pathway for volcanic products generated during the explosive and effusive activity of Stromboli volcano and is prone to intense morphological modifications and gravitational instability, which can culminate in mass-wasting events able to generate tsunamis. To detect SdF morphological changes a monitoring program was implemented by INGV. In May 2026, high-resolution bathymetric surveys, were performed using a marine USV equipped with EM2040P echosounder, highlighting the depositional/erosive structures of the 2007, 2024 and May 2026 lava deltas.

SBP29 from R/Vs SALLY RIDE, NEIL ARMSTRONG & THOMAS G. THOMPSON, & USCGC HEALY (WAGB-20). All are 3°X6° except for TGT (3°x3°). We will show ~100m penetration in hard rock, upslope-migrating bedforms in an anti-dune field, ability of a hull-mounted system to acquire a “spaghetti survey”, & comparison with other SBP & seismic systems. The SBP29 can be used to acquire wide angle seafloor reflection coefficient data, or equivalently Bottom Loss, using a single element.

Authors:

Daniel “DanO” Orange*, James Gibson, Eli Silver - U.C. Santa Cruz (*also Integral Consulting / ONE {Oro Negro Exploration LLC})

Toluwani Akande & Anand Hiroji – The University of Southern Mississippi

Charles Holland & Tim Sonnemann – Portland State University

Bjørnar Langli - KONGSBERG

Clay Whittaker (NAVO [ret.]), Madeleine C. Lucas & Kyle Becker (U. Washington)

In 2026, French’s Hydrographic Office (Shom) acquired its first deep-sea autonomous underwater vehicle, the Kongsberg Hugin Superior “Narval.” Sea acceptance tests were conducted in the Bay of Biscay to 4,500 m depth. This paper assesses the bathymetric quality and accuracy of its EM2040 MKII multibeam echosounder and HISAS 1032, according to IHO standards, as well as the detection capabilities. The system will significantly enhance high-resolution deep-water mapping and object detection.

The Woods Hole Oceanographic Institution's (WHOI) 6,000-meter AUV Sentry utilizes a unique hydrodynamic shape and four independently pivotable thruster fins, allowing it to hover, turn in place, and change pitch and roll dynamically to track extreme terrain. Sentry has operated successfully with the Kongsberg EM 2040 for the last seven years. This presentation shares the operational experiences, engineering choices, and lessons learned from integrating and running an EM 2040 multibeam system within Sentry’s distinct flight regime. Unlike traditional torpedo-shaped AUVs that prioritize stability at high speeds, Sentry’s high maneuverability and slower survey speeds introduce complex platform dynamics. We will discuss the specific mechanical and acoustic installation challenges within the vehicle’s packed lower payload bay, the integration with Sentry’s core navigation suite, and the resulting data quality. This includes the development of a custom, ROS-based software driver specifically designed for our application to control the EM 2040 and log its data. Furthermore, we will share insights into the EM 2040's performance and data fidelity when deployed at low altitudes over rugged features like hydrothermal vent fields and steep seamounts, offering practical takeaways for autonomous, high-resolution deep-sea mapping.

Nearly 20 years ago at FEMME Lisbon, the godfather of modern multibeam declared that the future of bathymetric sonar lay in synthetic bathymetry — yet industry uptake remains limited. Why? Using an evaluation dataset from the search for Pan Am Flight 526A, collected with a HUGIN AUV carrying HISAS 1032 and EM multibeam, we compare synthetic bathymetry with conventional MBES and photogrammetry, examine HISAS Bathy processing workflows, and ask how and indeed why should KONGSBERG move the industry forward.