A ship's hull is 150m long as has a wetted area of 5000 m^2. When it is encrusted with barnacles, it requires 7000 hp to overcome friction drag and move at 15 knots in seawater at 20C. What is the average roughness due to the barnacles? If the hull was cleaned up in a dry dock, what would be the Maximum speed with the same propulsive power?