The fouling of ships' hulls, whether by barnacles and seaweed or by slime-creating bacteria, is a major problem for shipping worldwide, and particularly for navies. It has been estimated that fouling of hulls can create such turbulence as a ship moves through the water that fuel consumption is increased by as much as 30 percent. Traditionally major users of ships, like the U.S. Navy, have attempted to resist fouling by painting hulls with paints containing copper or triorganotin, a tin-based compound. But these paints are highly toxic and can leach into the water, killing marine life. That's why their use increasingly is being prohibited.
A research group at Cornell University (Ithaca, New York), led by Christopher Ober, has developed two types of non-toxic paint, one hydrophilic and one hydrophobic, that effectively prevent fouling, whether by bacteria or barnacles. The paints act not only by minimizing adhesion by organisms but also by enabling hulls to become self-cleaning. As a ship moves through the water at 10 to 15 knots, the turbulence created removes the clinging barnacle or seaweed. Mr. Ober has been investigating the problem of marine fouling for the past decade for the U.S. Office of Naval Research (ONR).