Overview
The Client: Global Tanker Operator
Following a scheduled drydock in March 2021, a chemical/oil tanker owned by a global tanker operator began to show early signs of declining hull performance. Underwater inspections revealed significant slime and weed fouling across approximately 60% of the vessel’s vertical sides. This deterioration led to the requirement for two underwater cleaning events within a single drydock cycle – an immediate indicator of both technical misalignment and growing operational inefficiency.
Operating globally at average speeds of 13–14 knots, with activity levels around 60% and typical sea surface temperatures of approximately 30°C, the vessel was exposed to high fouling-risk conditions. In such environments, even minor misalignment in coating selection or application rapidly translates into increased hull resistance, higher fuel consumption, and operational disruption.
Recognising the escalating cost and performance implications, Safinah was engaged to redefine the vessel’s antifouling strategy ahead of its next scheduled drydock in China.
The Project
Safinah’s mandate extended beyond simple coating replacement. The objective was to fundamentally realign coating performance with the vessel’s actual operating profile – ensuring that the selected system could deliver consistent, predictable performance throughout the full docking cycle.
This required a shift from a product-led decision to a performance-led strategy – one grounded in real operational data, environmental exposure, and lifecycle cost optimisation.
The project scope included:
- Pre-drydock technical planning and risk assessment
- Fouling control strategy development
- Functional specification creation for supplier tendering
- Surface preparation optimisation
- Independent technical and commercial evaluation of coating systems
The ultimate goal: eliminate inefficiencies that directly translate into fuel penalties, offhire exposure, and avoidable maintenance interventions.
The Challenge
Following its previous drydock in 2021, the vessel began to show signs of suboptimal coating performance, driven by:
- Poor application quality during the last docking
- Increasing slime fouling across 60% of vertical surfaces
- Multiple hull cleaning interventions within a single cycle
- Global trading profile with high temperature exposure (~30°C) and moderate activity (~60%)
These factors introduced hidden operational penalties, including:
- Increased hull resistance = higher fuel consumption
- Growing risk of performance degradation between cleanings
- Potential for unplanned offhire due to hull condition deterioration
Despite not yet being flagged as an underperformer, the vessel was on a trajectory toward efficiency loss and rising operational cost.
Safinah's Approach
Safinah delivered a data-driven pre-planning and coating selection strategy, focused on maximising lifecycle performance.
- Operational Profile Modelling
Safinah began with a detailed assessment of the vessel’s historical operating data, including speed and activity profiles, trading routes, environmental exposure, and idle durations. This analysis revealed a critical performance requirement: the coating system needed to maintain effectiveness during extended static periods of up to 21 days without significant fouling accumulation – an essential factor in ensuring long-term hull efficiency.
- Functional Specification Development
Rather than selecting products based on generic performance claims, Safinah defined a functional specification grounded in real operating conditions. This specification established clear environmental performance thresholds, fouling resistance requirements, idle period tolerance, and expected coating lifespan. It provided a robust and objective framework for supplier tendering, enabling direct and comparable evaluation of competing systems.
- Targeted Surface Preparation Strategy
A condition-led surface preparation strategy was implemented to ensure precision in execution. Degraded coating areas were fully treated while sound coatings were preserved wherever possible, avoiding unnecessary blasting and recoating. This targeted approach reduced drydock scope, minimised downtime, and ensured that capital investment was directed only where it delivered measurable value.
- Independent Technical and Commercial Evaluation
Safinah conducted a rigorous, independent assessment of multiple supplier proposals against the defined functional specification. This included evaluation of coating chemistry and biocide composition, expected performance under actual environmental conditions, whole-life cost implications, and system complexity. Solutions that were misaligned with the vessel’s operational profile, required unnecessary additional layers, or lacked commercial efficiency were systematically rejected. Through this disciplined evaluation and subsequent commercial negotiation, Safinah guided the client toward a high-performance antifouling system precisely aligned with the vessel’s operational and environmental demands.
Project Results
By aligning coating design with real-world vessel behaviour, Safinah delivered clear and measurable operational and commercial benefits. The optimised antifouling strategy removed reliance on reactive interventions, eliminating unplanned hull cleaning events, reducing operational disruption, and improving confidence in maintaining charter commitments – ultimately lowering offhire risk.
At the same time, the improved coating performance maintained a smooth, foul-free hull condition, reducing hydrodynamic drag and preventing premature polishing, which translated into lower fuel consumption and sustained speed performance, delivering significant annual cost savings.
The vessel also transitioned to a predictive maintenance model, with zero requirement for underwater cleaning during the cycle, removing associated costs and ensuring consistent operational performance. From a capital perspective, Safinah ensured drydock investment was precisely targeted through condition-led surface preparation, avoidance of over-specified systems, and effective supplier negotiation – resulting in efficient CAPEX deployment and maximised lifecycle return.
This approach was fully validated at the vessel’s 2026 drydock, where inspection confirmed excellent coating condition with minimal fouling (<2%), demonstrating long-term performance stability and the effectiveness of the selected system.
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For more details about Safinah Services, please get in touch with one of our experts or email enquiries@safinah.com.
