Surface turbulence as in "on the surface of the water?"
It sounds like F. H. is refering to the surface of the sub.
He's talking about the blade surface even though the worst cavitation is at the blade tips and the propeller vortex.
More the boundary between the hull and the water. At low speed you have laminar flow. At higher speeds turbulent flow sets up. I used the term surface turbulence since my dealings with fluid flow is more through pipe and control valves. In the refinery noise is not an issue for the same reasons as a sub, more related to OSHA (85-90 dbA threshhold), and equipment damage due to vibration and erosion (a valve operating in cavitation is loud - and will not last long).