The U.S. Navy estimates that it spends around $50 million/year in additional fuel costs due to drag caused by bio-fouling — the attachment of algae, barnacles, and undersea flora to ships’ hulls. It’s a problem that has bedeviled sailors since boats were invented. I once made a pretty OK living doing underwater boat cleaning for local boat owners (high school days).
Funny thing: Whales get barnacles just like boats — but sharks don’t. A microscopic look at shark skin reveals a pattern of tiny rectangles arranged in geometric patterns, each topped with pointy bristles. The surface of a shark is very difficult for organisms to get a grip on. Since the organisms don’t have much time to live, they quickly move on, rather than wrestle with the texture.
Now researchers have found a way to replicate the texture of shark skin in great plastic sheets, which can be applied to ships’ hulls much like those big ads that cover entire buses. Not only do you get huge gains in fuel efficiency, but there’s a big enviro upside as well, as marine paint designed to minimize bio-fouling is full of copper, which sloughs off and sinks to the bottom of the sea. Everyone wins.