Spanish startup bound4blue designs and manufactures eSAIL®, a thick-profile, suction-assisted rigid sail that provides auxiliary wind propulsion for maritime vessels. Independently verified trials show fuel and emission reductions of 15–20 % on Odfjell’s Bow Olympus, with peaks up to 40 %, and daily fuel savings of up to 5.4 t on the Ville de Bordeaux ro-ro ship. The company has already installed its sails on seven ships and holds orders for twelve more, representing more than 50 eSAIL units. Customers include Maersk Tankers, Eastern Pacific Shipping, Odfjell, Klaveness Combination Carriers and BW Epic Kosan. With parallel production lines planned in Spain and China, bound4blue aims to manufacture several hundred sails annually and projects annual CO₂ savings exceeding 400,000 t by 2027. The newly raised capital positions the firm to transition from technology validation to full industrial scale-up while continuing R&D on additional wind-propulsion solutions.

Total raised

$68M

Funding rounds

4

Latest round

Equity

Latest activity

Dec 2025