Seasub

Seasub, formally incorporated as Seasub - Mergulho Profissional, Lda., operates as a specialized provider of commercial diving and underwater engineering services within the Portuguese maritime sector. Headquartered in Mafra with an operational footprint covering key national logistics hubs such as the Port of Lisbon, Setúbal, and Sines, the company supports the commercial shipping industry through a comprehensive suite of subsea maintenance and technical solutions. Its primary operational mandate involves the execution of complex underwater tasks that allow vessels to maintain seaworthiness and operational readiness without the need for immediate dry-docking, thereby facilitating the continuity of maritime trade routes that intersect the Iberian coast. The company’s core technical competency lies in the maintenance, repair, and detailed inspection of afloat structures and ocean-going vessels. Seasub employs professional diving teams equipped to perform rigorous in-water surveys, a service frequently verified by major international classification societies. These inspections utilize closed-circuit television (CCTV) and high-resolution photography to provide shipowners, insurers, and regulatory bodies with real-time assessments of a vessel's hull condition, rudder assembly, and propulsion systems. Such diagnostics are critical for monitoring structural integrity and ensuring regulatory compliance between scheduled dry-dock periods. Beyond diagnostics, the company executes essential physical interventions designed to enhance vessel performance. These include underwater hull cleaning and propeller polishing, technical processes aimed at removing marine fouling and restoring hydrodynamic efficiency. By smoothing propeller surfaces to precise standards, the company assists operators in reducing friction and optimizing fuel consumption. Operational capabilities further extend to specialized repair works such as underwater welding and cutting (anode replacement), the installation of cofferdams to isolate hull sections for internal repairs, and the blanking of sea chests and overboard discharges. The company also handles the replacement of sensitive instrumentation, including transducers and speed logs, while the ship remains afloat. In addition to maintenance and repair, the entity performs security-related underwater inspections, addressing the industry's requirement for hull screening against illicit attachments or tampering in sensitive port environments. By offering these technical interventions, Seasub enables vessel operators to address mechanical issues and maintenance requirements during scheduled port calls, minimizing expensive downtime. Through its portfolio of technical diving services, the company functions as a supporting node in the regional maritime logistics chain.