.truncate { white-space: nowrap; text-overflow: ellipsis; }

Underwater Surveys & Inspections

SGS provides a full range of inspection services from Class In-Water Surveys to Damage Inspections to Biofouling Inspections to Inland/Coastal Infrastructure Inspections.

UWILD & Class IWS

Every active trading vessel is required by its classification society to undergo a UWILD (Underwater Inspections in Lieu of Dry-docking) or Class In-Water Survey (Class IWS) periodically depending on the type of asset. These are required to ensure the structural and operational integrity of a marine asset throughout its life span. These inspections also ensure regulatory compliance in accordance with the IMO and Flag State.

Looking for Underwater Maintenance & Repair Services?

SGS has an unparalleled technical capability to deliver turn-key solutions at a global scale.
Contact Us

Inspection Services Include:

  • Underwater Inspection in Lieu of Dry-docking
  • Class In-Water Surveys
  • Biofouling Inspections
  • General Hull Inspections/ Underwater Examination (UWE)
  • Condition Surveys
  • Pre-Purchase Surveys
  • Sea Chest Inspections
  • New Zealand MPI Inspection Services
  • Impact Damage Inspections
  • Propeller Crack Detections
  • Underwater Structural Inspections
  • Seabed Surveys
  • Corrosion Surveys
  • NDE Inspections
  • Marine Construction Inspections such as dams, power stations, bridge inspections.

Case Studies

Hull Breach on Tanker

During cargo operations, a submerged pile pierced through the hull. SGS worked together with owner and class to develop repair plan that included the design and installation of an engineered cofferdam.

View full case study

Offshore Oil & Gas

A Blue-Chip oil & gas company incurred several defects and cracks in a critical attachment member of an FPSO’s hull – these defects required repair to allow continued operation.

View full case study

Skeg Ripped from Azipod

3 month out of dry dock, galvanic corrosion caused heavy cavitation/erosion damage on PORT and STBD side rudders.

View full case study

SGS Reseats Shifted Tailshaft Afloat and Executes a Stern Seal Repair

The client indicated that the tailshaft had shifted aft approximately 200 mm when the ship’s crew was doing maintenance on the shaft coupling. It resulted in the aft water seal losing contact with the liner, causing large amounts of water ingress into the stern tube.

View full case study

SGS Completes an Afloat Rudder Stock Seal Replacement

This complex underwater repair was completed to the client's satisfaction in 5 days in conjunction with various other repair works. SGS managed both the underwater and internal portions of this repair to ensure each phase was executed seamlessly.

View full case study

Underwater Propeller Blade Straightening – Cold Static Loading

SGS can restore your propeller blades as a permanent repair, to OEM design geometry by cold static loading with our underwater propeller blade press.

View full case study
No items found.
No items found.

Double Bow Thruster Removal by SGS

The benefits of removing a damaged bow thruster afloat are many. The customer was able to prevent further damage to the bearings and gears caused by the presence of seawater in the gear housing and the procedures allows the units to be overhauled prior to the vessels next dry-dock—or, they can be re-installed afloat by SGS, which would help to eliminate the need for additional tug cost.

View full case study

Afloat Bow Thruster Blade Seal Exchange by SGS

The project was executed with two SGS teams working around the clock. While the vessel trimming process was in motion, the team onboard the vessel began to drain the oil from the thruster while the dive team began removing the bow thruster tunnel gratings to gain full access to the bow thruster.

View full case study

Scrubber Overboard Spool Pipe Repairs with 5 Year Warranty

The installation of complete SOx scrubber systems is entirely possible without taking the vessel out of the water. SGS’s involvement is focused on precision cutting of the hull penetrations for the sea chest openings and overboard spool pipe installation below the waterline.

View full case study

SGS solves serious problems: Assisting a large, fully laden post-Panamax container vessel with steering issues

SGS solves serious problems: Assisting a large fully laden Post-Panamax container vessel with steering issues. SGS works with port authorities, class, and manufacturers to provide class-approved in-water float out removal, repair, and refit of a 110 mt rudder. Find out how our underwater inspection and survey services deliver practical, cost-effective solutions to a complex offshore problem. SGS works with port authorities, class, and manufacturers to provide class-approved in-water rudder float out removal, repair, and refit of a 110 mt rudder. Helping owners safely reduce their risk exposure and related costs that would include diversions, delays, and downtime.

View full case study

Galvanic Corrosion on Rudders

3 months out of dry dock, galvanic corrosion caused heavy cavitation/ erosion damage on PORT and STBD side rudders.

View full case study

Underwater Surveys & Inspections

Hull Cleaning

UWILD & Class IWS

Every active trading vessel is required by its classification society to undergo a UWILD (Underwater Inspections in Lieu of Dry-docking) or Class In-Water Survey (Class IWS) periodically depending on the type of asset. These are required to ensure the structural and operational integrity of a marine asset throughout its life span. These inspections also ensure regulatory compliance in accordance with the IMO and Flag State.

Inspection Services Include:

  • Underwater Inspection in Lieu of Dry-docking
  • Class In-Water Surveys
  • Biofouling Inspections
  • General Hull Inspections/ Underwater Examination (UWE)
  • Condition Surveys
  • Pre-Purchase Surveys
  • Sea Chest Inspections
  • New Zealand MPI Inspection Services
  • Impact Damage Inspections
  • Propeller Crack Detections
  • Underwater Structural Inspections
  • Seabed Surveys
  • Corrosion Surveys
  • NDE Inspections
  • Marine Construction Inspections such as dams, power stations, bridge inspections.

Looking for underwater maintenance and repair services?

Contact Us 24/7
Contact Us