It sounds like a method of boundary layer control used on aircraft. Some airplanes will have small pores in the skin in certain areas where small amounts of bleed air from the engines are pumped through to break up the boundary layer, thus reducing drag.
The boundary layer on an aircraft (or sub/ship hull) is the area right next the skin where at a microscopic level the air or water kind of "sticks" to the skin. If you can break up that "stickiness" then you can cut down on a lot of the drag so you can go faster with less power.
https://en.wikipedia.org/wiki/Boundary_layer
