Always interesting to test your theories.... I am sure there have been Whites near shore where I dive in RI. The bubbles and the big metal tank reacting with seawater is probably plenty to convince a shark we are of no interest to them long before they get in visual range. I have only seen a single brief glimpse of a dog fish on a night dive in RI. I know they are there, but they have no interest in us.... If I do see one, I will probably head for shore along the bottom at the quickest rate possible.
The free diving spear fishermen are probably at a much higher risk than noisy scuba divers....