hydrodynamic surface treatments (olympic swimsuits)

[Village_Idiot]

It has been a month or two since we've had a good argument over whether surface treatments, golf ball dimples or extremely smooth slick surfaces are most hydrodynamically efficient.

Since the Olympic swim events are fresh in many of our minds, what are folks' opinions on the "sharkskin" swimsuits and how their physics might apply to other hydrodynamic vessels, such as boats?

As I've mentioned in this forum before, I have recalled a study where researchers found that random protrusions along the inner surface of a pipe or sluice increased the velocity of water flowing through the pipe/sluice, something on the order of 15%. The same did not hold true for uniform projections, as they had an overall effect similar to a smooth surface. The theory was that the protrusions broke up small vortices along the surface before they could build into larger vortices and disrupt laminar flow. I believe the research summary appeared in the science journal NATURE sometime around 1993. I no longer have access to that periodical, so perhaps someone near a large library could dig up the specific info...