When it comes to building infrastructure beneath the surface of the water, commercial divers are the unsung heroes of marine construction. From ports and harbours to offshore oil platforms and aquaculture installations, these highly trained professionals play a critical role in ensuring marine construction projects are executed safely, accurately, and efficiently.
At GMC Diving, we’ve worked on a wide range of underwater construction projects along South Africa’s coastline — and beyond. Here’s an inside look at what commercial divers actually do on marine construction sites, and why their skills are indispensable.
1. Underwater Site Preparation
Before any construction work begins, divers are often deployed to conduct site surveys, clear marine growth, and remove underwater debris. These initial steps are crucial for ensuring a safe and stable work environment. Using tools like hydraulic cutters and dredging pumps, commercial divers prepare the seafloor for piling, concrete pours, or structure placement.
2. Installation of Marine Structures
Whether it’s placing precast concrete blocks, underwater pipelines, or steel piles, commercial divers handle tasks that demand precision and strength. With visibility often limited and working conditions challenging, their ability to interpret engineering drawings underwater and work in tandem with crane operators topside is essential to the project’s success.
3. Welding and Cutting Underwater
Specialised training allows commercial divers to perform underwater welding and oxy-arc cutting — skills often required for structural modifications or repairs. In marine construction, this can include joining steel sections, sealing cracks in submerged infrastructure, or removing obsolete components.
4. Concrete Placement and Grouting
In projects involving seawalls, slipways, jetties, or underwater foundations, divers assist in placing concrete via tremie pipes and ensure proper compaction in submerged environments. They also carry out grouting work, sealing anchor bolts and structural interfaces to ensure durability against ocean currents and corrosion.
5. Inspection and Quality Control
Divers are frequently called upon to conduct progress inspections and as-built verifications, capturing underwater footage or logging measurements to ensure that the work meets engineering specifications. Their feedback is vital for quality assurance and compliance with project milestones.
6. Maintenance and Repair
Long after a marine structure is completed, commercial divers are still needed for routine inspections, corrosion protection, and structural maintenance. Regular diving interventions can prevent costly failures by identifying early signs of wear and damage.
7. Health, Safety, and Environmental Compliance
All diving operations are carried out under strict health and safety protocols, with divers trained to manage the risks of working under pressure, poor visibility, and tidal currents. At GMC Diving, we follow industry best practices and comply with all South African maritime regulations, ensuring every project meets safety and environmental standards.
Why Choose GMC Diving for Marine Construction?
With years of experience across ports, aquaculture farms, and offshore energy projects, GMC Diving delivers turnkey diving solutions tailored to complex marine construction needs. Our team is equipped with the latest technology and certified to operate under the most demanding conditions.
Whether you’re installing a jetty, placing mooring blocks, or laying underwater infrastructure — we’re ready to dive in.
Need Professional Divers for Your Project?
Contact GMC Diving today to learn more about our commercial diving services or request a quote for your upcoming marine construction project.
📧 [info@gmcdiving.com]
📍 Based in Cape Town | Operating Nationwide