The HC12 is a remotely operated underwater vehicle (ROV) designed to clean the hulls of large vessels. The ROV attaches to the hull and moves across its surface, using high-pressure water and rotating cleaning discs to remove marine growth such as slime, algae, and shellfish. During cleaning, removed biofouling and wastewater are captured and transferred to a support vessel, where they are filtered and sterilized before discharge, reducing the risk of dispersal into surrounding waters. Operated remotely and equipped with cameras for underwater monitoring, the HC12 reduces dependence on diver-performed cleaning. Regular removal of biofouling helps maintain hull performance by reducing hydrodynamic resistance, which can contribute to lower fuel consumption and GHG emissions. The integrated cleaning and debris-recovery system also supports vessel operators in managing biofouling and its impact on marine ecosystems.