Underwater Inspection and Propeller Polishing at Koh Si Chang Anchorage

MaxiDive completed underwater inspection and propeller polishing support at Koh Si Chang Anchorage, including hull, appendage, rudder and propeller documentation.

MaxiDive completed Underwater Inspection and Propeller Polishing for a commercial vessel at Koh Si Chang Anchorage, Thailand. The underwater service was carried out using SSDE, HD 4K inspection system and hydraulic tools to document the vessel’s underwater condition and improve propeller blade surface condition.

The operation was performed under moderate sea state conditions with approximately 4 meters of underwater visibility. MaxiDive’s commercial diving team inspected hull plating, appendages, sea chest gratings, discharges, drain plugs, bilge keels, ICCP system, propeller assemblies, stern tube, rope guard and rudder assemblies.

Hydraulic tools were used to polish the propeller blade surfaces and improve the propeller surface roughness condition.

Underwater Inspection and Propeller Polishing: Service Scope

The requested underwater work included inspection of key underwater areas and propeller polishing. MaxiDive’s divers documented marine growth, coating condition, component security, propeller roughness and visible structural condition.

The main service scope included:

• underwater inspection of hull plating;

• appendage inspection;

• sea chest grating checks;

• discharge and drain plug inspection;

• bilge keel condition review;

• ICCP condition check;

• propeller blade, hub and boss inspection;

• propeller polishing using hydraulic tools;

• stern tube and rope guard inspection;

• rudder assembly inspection;

• underwater photo/video documentation.

This type of underwater service helps shipowners, ship managers and technical superintendents review vessel condition while the vessel remains afloat and plan further maintenance based on documented findings.

Propeller blade surfaces were polished as part of the underwater inspection and propeller polishing scope.

Hull Plating Condition

The hull plating was reported as covered by soft and hard marine growth. The soft marine growth consisted of slime and algae, while scattered hard marine growth was consistent with barnacles.

Loss of top coat, consistent with abrasion from the vessel’s anchor chains, was noted in the bow area. Bare steel was identified on the bulbous bow. Where visible, the paint throughout the vessel was found in good condition.

The flat bottom was reported free from grounding and abnormalities. The overall top coat and weld seams were intact. No concave weld seams were noted, and no damage or structural anomalies were reported.

Appendage Inspection

The underwater inspection also covered key appendages and support components. The transducers were reported securely in place, and the sea chest gratings were secure and fastened in place.

The discharges were free from abnormalities, and all drain plugs were secure with no leakage noted. The bilge keels were reported in good profile, with no contact damage or abnormalities.

The ICCP system was reported in good condition, with no contact damage or abnormalities noted. These findings provide useful technical confirmation for the vessel’s maintenance records and future service planning.

The propeller assembly was inspected and polished to improve surface condition and support vessel performance.

Propeller Assemblies and Polishing Result

The propeller blades, hub and boss were found covered by soft and hard marine growth. Before polishing, the propeller surface roughness was measured as grade “C” on Rubert’s Scale.

All blade surfaces and the hub were then polished using grit polishing discs and hydraulic tools. Upon completion, the average blade surface roughness was improved to Rubert “A”, supporting smoother propeller surface condition and better operational efficiency.

The stern tube was found free from structural anomalies. The rope guard was free from entanglement and was serviced by divers. All seal plugs were secure and fastened in place, with no abnormalities noted.

Rudder Assembly Inspection

The rudder assembly was covered by soft and hard marine growth. The paint coat appeared in fair condition, with no contact damage or abnormalities reported.

The niche area was heavily covered by barnacles. The rudder hatch was secure in place, and the drain plug was secure. The upper plate could not be inspected because it was above the waterline.

Documenting rudder condition is important for vessel maintenance planning, especially when marine growth, coating condition and underwater component security need to be reviewed without dry docking.

Why Underwater Inspection and Propeller Polishing Matter

Underwater inspection and propeller polishing help vessel operators maintain better awareness of hull and propulsion-related condition while the vessel remains afloat. Marine growth on the hull, rudder and propeller can increase drag, affect vessel performance and create additional maintenance requirements.

Propeller polishing is especially important because blade surface roughness can affect propulsion efficiency. By polishing the propeller from Rubert “C” to Rubert “A”, the operation helped improve the blade surface condition and provided clear documentation for the vessel’s technical team.

For vessel operators, this service supports:

• underwater condition review without immediate dry docking;

• documentation of marine growth and coating condition;

• propeller surface improvement;

• inspection of hull, appendages and rudder areas;

• maintenance planning based on visual records;

• reduced uncertainty before future operations.

MaxiDive Commercial Diving Support in Thailand

MaxiDive provides underwater inspection, propeller polishing, hull cleaning, sea chest cleaning, underwater measurement, emergency repair and commercial diving support for vessels operating in Thai ports and anchorages.

This Underwater Inspection and Propeller Polishing operation at Koh Si Chang Anchorage demonstrates MaxiDive’s ability to support vessel operators with professional commercial diving, HD underwater documentation, hydraulic tools and practical marine maintenance reporting.

Conclusion

The Underwater Inspection and Propeller Polishing operation at Koh Si Chang Anchorage provided the vessel’s technical team with documented findings across hull plating, appendages, propeller assemblies, stern tube, rope guard and rudder areas.

MaxiDive’s commercial diving team completed the requested inspection, polished the propeller from Rubert “C” to Rubert “A”, and delivered underwater documentation to support future maintenance planning and vessel condition review.

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Underwater Inspections & Surveys

Hull Cleaning & Propeller Polishing

Commercial Diving Services

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