Installation, repair and maintenance of ships' and vessels' hulls; installation, repair, and maintenance of ultrasonic biofouling management systems and ultrasonic antifouling systems for ships and vessels; monitoring the condition of ultrasonic biofouling management systems for repair and maintenance purposes; monitoring the condition of ships' and vessels' hulls for maintenance and repair purposes, especially in relation to biofouling; monitoring the build-up of biofouling for maintenance a...