Poole Harbour Commissioners (PHC) Poole Port Apex was contracted by the Harbour Engineer at Poole Harbour Commissioners (PHC), located in Poole Port, Dorset, UK. The project, spanning over one year, involved a detailed subsea inspection of nine commercial quays, followed by targeted remedial works on a single quay wall. Leveraging our expertise in underwater engineering and our own dive support vessel, we delivered high-quality, engineering-level reports and executed precise repairs to ensure the structural integrity and operational safety of the port infrastructure. ​ Objectives and Challenges Poole Harbour is one of the UK's busiest natural harbours, handling a wide range of commercial vessels and requiring robust maintenance to mitigate the effects of tidal erosion, corrosion, and daily wear. The Harbour Engineer sought a thorough assessment to identify potential risks and recommend remedial actions. Key challenges included: Conducting inspections in a dynamic tidal environment with varying depths and visibility. Accurately assessing subsea elements such as seabed conditions, structural damage, and corrosion without disrupting port operations. Providing actionable, engineering-standard reports for each quay, including recommendations for remedial works. Executing high-pressure jetting and repairs on a Larsen sheet pile wall, involving subsea welding and anode installation, while adhering to strict safety and environmental protocols. ​ Our Approach Phase 1: Subsea Survey and Inspection Utilising our company-owned vessel as a stable dive platform, we conducted comprehensive surveys across the nine commercial quays over the course of the project. The inspections encompassed: Depth and Seabed Analysis: Precise measurements of water depths and evaluation of seabed conditions, including sediment build-up, spalling, and any irregularities that could affect vessel berthing. Structural Integrity Assessment: Detailed examination for damage, debris accumulation, corrosion, holes, and degradation in quay walls and foundations. Quay Furniture and Safety Equipment: Inspection of bollards, fenders, ladders, and life-saving apparatus to ensure compliance with safety standards. Subsea Thickness Readings: Employing ultrasonic gauges to measure material thickness and identify areas of thinning due to corrosion. ​ Each quay was documented with high-resolution underwater photography and video, supplemented by real-time data logging. Our findings were compiled into individual engineering-level reports, complete with annotated diagrams, risk assessments, and prioritised recommendations for remedial works. This phase was completed efficiently, minimising downtime for the port. ​ Phase 2: Remedial Works on Larsen Sheet Pile Wall Following the inspections, we focused on a single quay wall exhibiting significant corrosion and structural vulnerabilities. The process, conducted over several months, included: High-Pressure Jetting: Using specialised HP jetting equipment to remove marine growth, rust, and debris from the Larsen sheet pile wall, preparing the surface for detailed assessment. Visual and Ultrasonic Inspections: Post-jetting visual checks combined with ultrasonic thickness readings to quantify metal thinning and locate holes or weakened sections. Subsea Repairs: Targeted repairs to corroded areas and holes via subsea welding techniques, restoring structural strength with minimal environmental impact. Anode Installation: Fitting 416 subsea sacrificial anodes to provide cathodic protection against future corrosion, extending the asset's lifespan. All works were carried out by our experienced divers, supported by topside engineering oversight, ensuring precision and safety throughout. ​ Results and Benefits The year-long project was delivered on schedule and within budget, providing PHC with invaluable insights into their infrastructure. Key outcomes included: Enhanced safety and operational reliability for the nine quays, with identified issues addressed proactively. Extended service life of the treated quay wall through corrosion protection, potentially saving significant future repair costs. Detailed reports that informed PHC's long-term maintenance strategy, enabling data-driven decision-making. Minimal disruption to port activities, demonstrating our commitment to efficient, non-intrusive operations. Client feedback highlighted our professionalism, technical expertise, and the clarity of our reporting, reinforcing our reputation as a trusted partner in marine engineering.