Debmarine’s new crawlers will increase annual production on its flagship vessel, the Benguela Gem, by an estimated 80,000 carats.
The next-generation 800NB crawlers each weigh about 370 tonnes, compared with the 296-tonne units they replace.
They are designed to improve mining efficiency by 20 per cent and extend pump life by 30 per cent. Development costs are estimated at N$1.1 billion.
The Benguela Gem currently recovers around 500,000 carats annually.
With the crawler upgrade, output is expected to rise further as the older vessels, Grand Banks and Coral Sea, are retired.
The crawlers are mounted on the vessel and collect diamond-bearing gravels from the seafloor, pumping them through armoured hoses to onboard processing plants.
The ship, equipped with the upgraded crawlers, will return to Namibian waters by the end of September 2025, following sea trials in Cape Town.
Debmarine will rotate the crawlers between operations and refurbishment to maintain production.
Marine diamonds account for the majority of Namibia’s diamond output.
The new crawlers are giant, remotely operated subsea vehicles controlled from the vessel’s bridge.
Each machine uses a powerful cutting head to break through gravel and cemented sediments on the ocean floor.
Diamond-bearing material is then vacuumed up through reinforced hoses to the ship for processing.
The crawlers are designed for greater traction and stability, allowing them to mine continuously in rougher seabed conditions while delivering higher throughput and lower downtime.
Unlike vertical drill ships, Debmarine’s crawler systems skim and vacuum diamond-bearing sediments across pre-modelled panels, lifting material through an armoured hose to the vessel for dense-media separation and X-ray recovery.
The next-gen 800NB design focuses on higher throughput in coarser, cemented gravels, reduced wear rates in the pump and pipe string, and improved traction and manoeuvrability to keep mining in sea states that previously forced downtime.
Debmarine is Namibia’s single largest diamond producer by value.
With crawlers that mine faster and break down less, the company projects higher annual recoveries and better vessel utilisation, supporting royalties, taxes, and local supply chains.
This is key as older ships retire and the country leans more heavily on next-generation assets to sustain marine output.
Officials have framed the crawler upgrade as a way to maintain national production targets while improving efficiency.
Chief Executive Officer Willy Mertens said the deployment of the new crawlers underscores Debmarine’s commitment to innovation and Namibia’s economy.
“These new systems are built to keep us at the forefront of marine diamond recovery. They not only deliver more diamonds but also enhance efficiency and reliability, which ensures continued value for Namibia and our stakeholders,” he noted.
At the 2025 Mining Expo in Windhoek, Mertens stressed that the crawler programme fits into a broader strategy that extends beyond output.
He highlighted the role of new technology in creating skilled jobs, training Namibians in advanced engineering and marine operations, and developing local suppliers who can support complex offshore systems.
He said Debmarine is committed to reinvesting in people and infrastructure to make sure Namibia benefits directly from marine diamond revenues.
“We see technology as not just about more diamonds, but about building capacity and leaving a legacy for Namibians. Every upgrade must translate into jobs, training, and wider participation in the value chain,” Mertens told delegates.
Debmarine’s production has historically ranged between 1.5 and 1.7 million carats annually over the past decade. Output dipped to about 1.1 million carats in 2020 during the pandemic but rebounded to pre-COVID levels in 2022 with the arrival of the Benguela Gem, which alone contributes around 500,000 carats a year.
Recent years have seen production stabilise at around 1.5–1.6 million carats, with the new crawlers expected to push totals higher from late 2025 into 2026.
The new crawlers are purpose-built and heavier than their predecessors, designed specifically for the Benguela Gem and optimised for Namibia’s toughest seabed.
They are expected to deliver a 20 per cent improvement in mining rate and a 30 per cent improvement in pump life, meaning more carats recovered with fewer stoppages.
At about 370 tonnes each and with an investment cost of roughly N$1.1 billion, they represent the largest subsea mining tools ever deployed by Debmarine.
Integration is now complete, and the Namibian deployment is scheduled for late September 2025, following the return of the Benguela Gem from maintenance.
