When it comes to ship efficiency, size matters—specifically, the size of barnacles on your hull significantly impacts hull roughness. While most underwater inspections focus on identifying the presence of biofouling, understanding the actual dimensions of these organisms is critical for predicting their impact on fuel consumption and vessel performance.

Atlantic Tech & Candy, in partnership with Blue Atlas Robotics and their ROV Sentinus 2, has developed an approach to measure barnacle dimensions during routine biofouling inspections using stereo camera technology. This capability transforms standard inspection footage into quantitative data that operators can use for maintenance planning and performance monitoring.

Why Barnacle Size Matters More Than You Think

Not all biofouling has the same impact on drag. Research shows that barnacle height is the dominant factor in determining added resistance—far more than coverage area alone. A hull with 10% coverage of 5mm-tall barnacles can experience similar drag penalties as one with 50% coverage of smaller 1.25mm barnacles. This means that knowing how big your barnacles are, not just where they are, is essential for accurate performance predictions.

Hull roughness is typically characterized by parameters like equivalent sand-grain roughness (k_s), which directly influences drag calculations in performance models. By measuring barnacle dimensions, operators can estimate these roughness values and better understand the fuel penalty they’re facing.

From Inspection Video to Quantitative Hull Roughness Measurements

For a typical inspection frame at 70cm distance, the system achieves approximately 0.5mm resolution—sufficient to characterize barnacles ranging from a few millimeters to several centimeters in diameter.

Handling Real-World Complexity

Barnacles don’t always grow as isolated individuals. Dense colonization often results in clusters where boundaries between organisms aren’t visible. The analysis approach accounts for this by using statistical methods to estimate the number of individual barnacles within merged clusters, providing more accurate population counts and size distributions.

In one analyzed frame, the system detected 180 distinct regions but estimated these represented approximately 462 individual barnacles—revealing that nearly one-third of the detected areas were actually clusters. This level of detail helps distinguish between light fouling with a few large barnacles and heavy colonization with many smaller organisms.

Practical Applications

This measurement capability integrates naturally into existing inspection workflows. The same ROV footage used for visual documentation now also provides:

Rather than relying on subjective assessments like “light,” “moderate,” or “heavy” fouling, operators gain specific measurements: median barnacle diameter, coverage percentage, and estimated roughness values that can feed directly into performance models.

About the Partnership

This work represents a collaboration between Atlantic Tech & Candy and Blue Atlas Robotics, combining expertise in marine efficiency analysis with advanced ROV capabilities. The Sentinus 2 ROV’s stereo camera system provides the foundation for these measurements during standard underwater inspections.

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Underwater hull inspection involves multiple parties with different responsibilities and access needs. Shipping companies own vessels and need oversight of their entire fleet. Fleet managers coordinate inspection activities across multiple vessels and organizations. Service providers conduct the actual inspections and need access to specific projects they’re working on. Each party requires different levels of access to vessel data, inspection projects, and reporting capabilities.

We’ve implemented a comprehensive Role-Based Access Control (RBAC) system for HullSight Ultimate that provides granular control over what users can see and do in the application. The system operates on three distinct levels, each serving a specific purpose in the security architecture.

The Three Permission Levels

Unrestricted Access Option

Roles can be configured with an “unrestricted access” flag. When enabled, users with that role bypass object-level filtering while still respecting CRUD permissions. This is useful for organizations that want certain roles to see all data without the complexity of access group assignments. For example, a Fleet Manager role with unrestricted access can view all projects in the tenant, but if they don’t have delete permission, they still cannot delete any projects. This separates the “what can you do” question (CRUD permissions) from the “what can you see” question (object-level access).

Access Groups and Hierarchical Filtering

Access groups simplify permission management by grouping organizations, vessels, and projects together. Instead of assigning individual users to individual projects, administrators assign users to access groups, and those groups contain the relevant entities.

The hierarchical nature means you can grant access at any level:

• Grant access to an organization → user sees all vessels and projects in that organization
• Grant access to a vessel → user sees all projects for that vessel
• Grant access to specific projects → user sees only those projects

Users can belong to multiple access groups, and their permissions are combined. If one access group grants access to Organization A and another grants access to Project X (which isn’t in Organization A), the user gets access to both.

Entity Groups for Bulk Management

Organization Groups, Vessel Groups, and Project Groups allow administrators to bundle entities together for easier permission assignment. Instead of individually selecting 50 vessels, you can create a “Container Fleet” vessel group and assign it to an access group in one action.

Audit Trail

Every permission change is logged in a comprehensive audit trail. The system tracks who made what changes, when they were made, and from which IP address. This includes:

• Role assignments and removals
• Access group membership changes
• Permission modifications (navigation items, CRUD permissions)
• Entity access grants and revocations
• Role and access group creation, updates, and deletions

Each audit log entry captures the user who performed the action, the affected user or entity, and detailed information about what changed. For role assignments, the system records both the old and new roles. For entity access changes, it logs the entity type, entity IDs, and whether access was granted or revoked.

The audit interface displays these logs in a filterable table with color-coded action chips: green for additions and grants, red for deletions and revocations, orange for updates, and blue for copy operations. Only tenant administrators can access the audit logs, ensuring that the security trail itself remains secure.

The audit logging is designed to never interfere with operations. If logging fails for any reason, the main operation continues successfully. This ensures that audit functionality doesn’t become a point of failure for critical permission changes.

Benefits of This Approach

Separation of Concerns: The three-level system cleanly separates module access, action permissions, and data visibility. This makes it easier to reason about what a user can and cannot do.

Flexibility: Organizations can choose between unrestricted roles (simpler, broader access) and restricted roles with access groups (more complex, tighter control) based on their security requirements.

Hierarchical Efficiency: Granting access at the organization level automatically cascades to vessels and projects, reducing administrative work while maintaining security.

Role-Based Management: Permissions are tied to roles, not individual users. When you need to change what Inspectors can do, you update the Inspector role once rather than updating dozens of user accounts.

Scalable: The system uses efficient database queries with set operations and proper indexing, ensuring performance even with large numbers of users and entities.

Gradual Adoption: Organizations can start with unrestricted roles and add object-level restrictions later as their needs evolve. The system doesn’t force complexity on those who don’t need it.

The RBAC system provides the foundation for secure multi-user collaboration while maintaining the flexibility to adapt to different organizational structures and security requirements.

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In December 2025, we successfully demonstrated the power of combining advanced robotics with AI-driven analysis during a large-scale hull inspection in Aarhus, Denmark. In partnership with Blue Atlas Robotics (BAR), we inspected a 200m container vessel, proving that comprehensive biofouling assessments can be both rapid and highly detailed.

The Inspection: Precision at Speed

The physical inspection was carried out by BAR using their Sentinus ROV. Known for its efficiency, the Sentinus covered almost the entire port and starboard sides of the vessel—scanning 49 distinct hull sections and niche areas—in just about 4 hours.

The Analysis: Powered by HullSight Ultimate

With the physical scan complete, the focus shifted to data analysis using HullSight Ultimate. We processed 5.5 GB of video material, consisting of individual video files for each of the 49 sections.

The speed of the workflow was unprecedented. From the start of the video upload to the delivery of the final report, the entire process took approximately 1 hour.

During this short window, HullSight Ultimate:

• Automatically processed the video footage.
• Extracted roughly 850 representative images.
• Analyzed every image using our advanced biofouling AI model.
• Compiled the results into a comprehensive 54-page PDF report.

Actionable Results

Conclusion

This operation in Aarhus highlights the synergy between Blue Atlas Robotics’ hardware and HullSight Ultimate’s software. Together, we delivered a complete, high-fidelity inspection of a 200m vessel with minimal downtime, turning gigabytes of raw video into a finalized, actionable report in record time.

Interested in a Large Scale Hull Inspection? Contact Us!