Data centres are the backbone of our digital world, powering everything from cloud computing to streaming services.
However, one of the most pressing challenges they face is the cooling of server racks. Traditional cooling methods can be energy-intensive and environmentally unsustainable. As the demand for data storage and processing continues to surge, innovative solutions are needed. One such solution gaining traction is the use of the ocean as a natural coolant.
Why the ocean?
Seawater cooling uses the ocean’s natural temperature to cool data centres. By harnessing the cold temperatures of the ocean, data centres can lower their overall energy consumption and minimise freshwater usage, which is crucial in areas facing water scarcity. Additionally, ocean-cooled facilities can benefit from lower latency for coastal users, reduced land use, and decreased demand on local infrastructure, making them an attractive option for urban areas. There are several pioneering projects that show the potential of ocean-cooled data centres. First of its kind, Microsoft’s Project Natick launched in 2015.
The research initiative aimed at exploring the feasibility of underwater facilities. Although Microsoft discontinued the project in 2024, the insights gained have paved the way for future innovations in the field. In June 2025, Hicloud Technology launched a commercial-scale underwater data centre project powered by offshore wind.
This facility utilises seawater-based cooling, which, combined with other features, Hicloud claims can enhance energy efficiency by up to 60%. This project represents a significant step toward integrating renewable energy with innovative cooling solutions.
Another example is Subsea Cloud, which operates in Port Angeles, Washington. The company has developed pressure-equalised pods for underwater colocation, reporting a 40% energy savings and a 98% reduction in latency for coastal users. However, Subsea Cloud faces challenges related to maintenance and the management of fluctuating water temperatures.
Interestingly, ocean data centres are not only underwater, but also floating. For example, Nautilus Data Technologies (NDT), a California-based startup, opened a floating barge data centre in Stockton in 2021. The facility aims to reduce energy consumption, eliminate evaporative water loss, and provide operational flexibility in ports or harbors.
As of 2025, NDT remains active in Stockton and is exploring additional sites. The Google Barge Project is still in the exploratory phase, investigating the construction of modular, floating data centres on barges or ships.
Similarly, Keppel Data Centres is working on a Floating Data Centre (FDC) project in Singapore, which not only helps free up land for urban uses but also integrates hydrogen and solar energy solutions.
Challenges on the horizon for data centres
Despite the promising advancements, several challenges remain for ocean-cooled data centres. Maintenance of underwater facilities requires specialised retrieval and handling systems, complicating operations. Additionally, variability in water temperatures can pose management challenges, necessitating advanced monitoring and control systems.
Environmental concerns are also looming: the warm discharge from these facilities could potentially affect marine ecosystems, raising questions about regulatory permits and environmental sustainability. Furthermore, the scalability of ocean-cooled data centres to match the size and capacity of large land-based facilities remains uncertain, as the technology is still in its infancy.
The data centre industry is transitioning from proof-of-concept projects to commercial deployments of ocean-cooled facilities. As technology advances and the demand for sustainable solutions grows, we can expect to see further innovations in this space.
