A nearly 300-meter passenger vessel operating in a high-traffic cruise terminal required the installation of a new bow thruster to support maneuverability and safe port operations. Due to the vessel’s size, operational schedule, and the need to avoid drydocking, the work had to be performed underwater while the ship remained afloat. Subsea Global Solutions was engaged to execute the installation using commercial diving techniques, ensuring minimal disruption to the vessel’s operational timeline.

The Challenge

The installation of a new bow thruster on a vessel of this size presented several technical and operational challenges. All work had to be conducted within the confines of the thruster tunnel, requiring precise underwater alignment, welding, and rigging in limited visibility conditions. The project involved multiple phases spread across several operational windows, demanding consistent coordination with shipboard engineering staff and strict isolation procedures to ensure diver safety. Additionally, the installation required certified welding, nondestructive testing, and protective coatings to meet class and operational requirements, all while maintaining schedule certainty within an active cruise port environment.

Scope of Work & Solution

Subsea Global Solutions executed a phased underwater installation of the bow thruster system over multiple shifts. The scope included Installation of an internal cofferdam, thruster unit, and stay plate/strut, as well as a bolts & keeper bar, and filling of the unit with oil. Epoxy coatings were applied to protect newly welded components, followed by magnetic particle inspection (MPI) to verify weld integrity. Divers also removed blade chalks and pad eyes to prepare the thruster for commissioning, installed port and starboard tunnel gratings, and completed anode installation where structural conditions allowed. Throughout the project, Subsea Global Solutions maintained daily coordination meetings with vessel personnel, completed full photo documentation, and ensured all work was performed in accordance with safety, quality, and class requirements.

Conclusion

The underwater bow thruster installation was completed successfully, restoring the vessel’s maneuvering capability without the need for drydock. Subsea Global Solutions delivered the project safely, efficiently, and in alignment with the vessel’s operational schedule, demonstrating the value of experienced commercial diving teams for complex underwater installations on large passenger vessels. The completed work supported the vessel’s return to service with minimal operational impact.

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Underwater Demountable Thruster Exchange Services

Subsea Global Solutions’ Underwater Demountable Thruster Exchange (UDTE) service enables the installation, removal, and replacement of bow and stern thrusters while vessels remain afloat and in service, eliminating the need for drydocking. Using proven commercial diving techniques, certified underwater welding, precision rigging, and nondestructive testing, our teams safely execute complex thruster exchanges on large passenger and commercial vessels with minimal operational disruption. This cost-effective solution reduces downtime, preserves schedules, and ensures vessels maintain critical maneuvering capability. Learn more about our underwater demountable thruster exchange capabilities here.