Objectives of the service
Due to the increasing volume of goods traffic, the maritime industry faces a growing need for regular, costefficient ship hull inspections. Close-up visual inspection for biofouling, cleaning, and maintenance is of utmost importance. Regular autonomous inspections of the hull's condition using autonomous underwater vehicles (AUV) can reduce these costs and contribute to more cost-efficient and environmentally friendly shipping.
Furthermore, regular monitoring and removal of fouling helps limit the spread of invasive marine species.
The proposed solution is a fully autonomous inspection system for underwater objects and structures consisting of an AUV and a supporting autonomous surface vehicle (ASV).
Its key value is the systematic inspection of large, difficult-to-access areas in minimum time, capturing details divers cannot. This technology provides more extensive, safer, and rigorous inspection by increasing the speed and frequency with which biofouling and anomalies are detected and digitally reported.
Furthermore, the severity of irregularities can be indicated so that users know how to respond. By maximizing resources, a new level of maritime safety and pollution prevention is ensured.
Within the HAISat project, a feasibility study will be conducted to test and validate the use of autonomous inspection technology, enhanced with satellite navigation and communication capabilities, on designated vessels.
Users and their needs
There are two key customer groups for the proposed autonomous underwater inspection technology service: inspection service providers and end-users (ship owners and harbour authorities).
Current pain points for subron’s direct customers (Inspection Companies):
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Maneuvering in confined spaces raises accident and equipment failure risks, endangering dive teams.
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Poor visibility (down to 50 cm) hinders navigation, hazard detection, and instrument reading (e.g., depth, time, decompression, gas pressure).
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Lack of precise positioning complicates creating valuable data for end-users.
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Slow communication and data transfer from remote anchorage spots prevent real-time preprocessing onshore.
Current pain points for subdron’s end-users (Shipping Companies and Maritime Authorities):
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High inspection costs
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Significant downtime especially for large vessels.
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No recurring, easy-to-interpret data impedes decision-making and predictive maintenance.
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Late access to data acquired (after hours or days), impossibility informed decisions after the inspection.
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Ship hull biofouling introduces invasive species, harming aquatic ecosystems.
End-User Requirements (from interviews):
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Shorter, cheaper inspections to enable more frequent checks for better awareness and preventive maintenance.
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High spatial accuracy (≤10 cm) to precisely map results and anomalies.
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Clear, processed digital results for improved decision-making.
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Faster sharing of detailed reports with management to speed up interventions.
The offer is initially aimed at European users.
Service/ system concept
The inspection system's core is an autonomous underwater vehicle (AUV) with sensors for high-resolution imaging of underwater structures and vessels.
An autonomous surface vehicle (ASV) operates on the water surface and maintains constant acoustic contact with the AUV.
The USBL (ultra short baseline) transceiver on the ASV uses acoustic signals to measure distance and bearing to the transponder on the AUV. At the same time, it enables acoustic communication between both vehicles. This allows the ASV’s highly accurate position to be transmitted to the AUV and used for permanent position correction.
This correction helps compensate for position drift on board the AUV and improves trajectory control, navigation, and localization. It also ensures that visual inspection data can be accurately linked to the correct location on the vessel, allowing anomalies to be spatially assigned.
After surfacing, the AUV sends the data to the ASV via local Wi-Fi, and the ASV forwards it to the cloud via satellite communication.
The cloud-based processing enables quick evaluation and possible mission readjustment, especially in remote areas with limited or no land communication coverage. At the end of the mission, the processed inspection data is provided to the customer for assessment and decision-making.
Space Added Value
Space technologies (SatNav and SatCom) play a pivotal role in enhancing the proposed autonomous inspection solution and will be integrated and evaluated in the HAISat feasibility study.
These technologies provide support in two areas:
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Precise Positioning
High-accuracy positioning is crucial for inspection efficiency and data quality. Underwater, GNSS signals are not available and internal positioning systems drift over time, requiring corrections. An ASV with GNSS (global navigation satellite system) provides cm-level positions to the AUV via USBL (ultra-short baseline), compensating internal positioning sensor drift for better control, collision avoidance, and precise data georeferencing; even in featureless areas near ships where SLAM (simultaneous localization and mapping) struggles.
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Reliable Communication
SatCom overcomes network gaps in remote areas (e.g., anchorages). Data from the AUV's internal storage transfers via Wi-Fi to the ASV, then via e.g. Starlink to cloud computing facilities and the ship owners. This enables real-time monitoring, quick anomaly resolution, and cloud processing for minute-scale reports instead of hours.
Current Status
HAISat reached an initial project milestone through collaboration with a leading German shipowner. During routine harbour operations, hull images of a container vessel were collected using an autonomous underwater vehicle (AUV) equipped with the HAISat visual payload. The acquired dataset highlights key challenges related to localization and data acquisition under real-world operational conditions.
In addition, an autonomous surface vehicle (ASV) was procured and equipped with a GNSS antenna, an USBL
system, and Starlink communication capabilities. Control tests conducted at subdron’s facility in Bregenz, AT
confirmed precise surface positioning, stable underwater communication links, and reliable satellite-based data
transmission
The upcoming project steps include the refinement of the SLAM (simultaneous localization and mapping) algorithm, the integration of the AUV – ASV collaboration as well as conclusive field demonstrations in Q3/2026.