Bound4blue has secured US$44m in new funding to accelerate the industrialisation of its suction sail technology as market demand grows for scalable, near-term decarbonisation solutions.

The round, announced on 9 December 2025 and backed by maritime corporates, shipowning families, climate-focused investors and government capital, was led by OCTAVE Capital and Katapult Ocean. New investors include Motion Ventures, the Odfjell family office and ReOcean Fund, led by the Prince Albert II of Monaco Foundation and Monaco Asset Management, alongside existing backers Shift4Good, GTT Strategic Ventures, KAI Capital and CDTI (Innvierte SICC).

Bound4blue said the investment will enable it to expand manufacturing capacity through parallel production lines in Spain and China, strengthen R&D efforts and advance its broader growth roadmap.

“This round signals a new phase for bound4blue. Earlier stages focused on proving the technology and validating its impact; now this new capital reinforces the long-term backing we already have from investors who understand shipping and share our industrial vision and the role this technology will play across the fleet,” said José Miguel Bermúdez, CEO & Co-Founder of bound4blue. He added that the company is positioned for “sustained global deployment” as suction sail demand increases.

The company has installed its eSAIL® suction sails on seven vessels, with 12 ships in its orderbook representing more than 50 sails. Its client base includes Maersk Tankers, Eastern Pacific Shipping, Odfjell, Klaveness Combination Carriers and BW Epic Kosan.

According to bound4blue, independently verified operational assessments show consistent fuel and emission reductions, including daily fuel savings of 1.7 tonnes and peaks of 5.4 tonnes on Ville de Bordeaux, and average savings of 15–20% on Odfjell’s Bow Olympus, with voyage-leg peaks reaching up to 40%.

By 2027, the company expects to deliver annual CO₂ savings of more than 400,000 tonnes, with over 570,000 tonnes avoided in total between 2024 and 2027.

May Liew, Chief Executive Officer at OCTAVE Capital, said: "We invested in bound4blue because wind propulsion systems have moved from promising innovation to proven, scalable climate infrastructure. For the maritime sector, where long-dated fuel transitions remain critical but still years from wide-scale adoption, this technology provides the real and immediate carbon emissions reductions needed right now."

Jonas Skattum Svegaarden, CEO at Katapult Ocean, added: "After years of looking for the right opportunity in this space, we were driven to invest in bound4blue as wind propulsion has clearly shifted from experimental concept to bankable decarbonisation tool."

Suction sails convert wind into thrust, reducing engine load and fuel use, improving compliance with regulatory frameworks such as CII, EEXI/EEDI, FuelEU Maritime, and the EU ETS. The technology is being fitted to both existing vessels and newbuild designs as the sector moves into what many describe as a “retrofit decade.”

Founded in 2014, bound4blue is headquartered in Cantabria, Spain, with offices in Barcelona and Singapore.