Based in Piraeus, Greece, Thalassa Holdings operates as a specialized marine contractor and offshore services provider, integrating a diverse range of subsea and surface capabilities. Although the corporate holding structure was formally established in 2021 to consolidate its activities, the organization’s operational lineage extends back several decades through its varied divisions. The company functions as a central management entity for specific subsidiaries dedicated to commercial diving, subsea cable engineering, offshore energy support, and marine salvage.
The company’s primary operational focus revolves around complex underwater and maritime projects. In the sector of commercial diving, it executes a broad spectrum of tasks ranging from ship maintenance—such as hull cleaning and propeller polishing—to underwater welding and civil engineering works for port infrastructure. Its capabilities extend into the offshore oil and gas industry, where it provides inspection, maintenance, and repair services for refineries, drilling rigs, and production platforms. This includes the deployment of Remotely Operated Vehicles (ROVs) and saturation diving teams to support deeper subsea infrastructure.
A significant portion of Thalassa Holdings' activity is dedicated to the subsea cable market. The firm supports power and fiber optic cable manufacturers with installation, protection, and repair solutions, including unexploded ordnance (UXO) surveys and seabed engineering. Parallel to these construction and maintenance roles, the company maintains a permanent readiness for emergency response. Its salvage and wreck removal division assists major global salvors with heavy lifting operations, refloating grounded vessels, and managing oil spill responses to protect the marine environment.
To execute these operations, Thalassa Holdings utilizes a specialized fleet of multi-purpose vessels. Its assets include shallow draft workboats, diving support vessels, dredging barges, and pontoons, alongside Anchor Handling Tug Supply (AHTS) units capable of supporting offshore logistics. The company maintains extensive facilities in Piraeus, as well as branch locations in Elefsis, Lavrion, and Crete, serving as logistical hubs for deploying personnel and containerized equipment worldwide. By combining long-standing technical expertise with a consolidated management framework, the company supports maritime operators, energy majors, and port authorities with critical infrastructure projects and emergency marine services on a global scale.