Pools and Shipping Lanes

Speedo's LZR swimsuit grew out of earlier shark-skin experiments, but its speed did not come from denticles. Speedo dropped the textured surface and leaned on stretchy polyurethane panels that squeezed the body into a streamlined shape and trapped a little air for buoyancy. It worked almost too well. After a wave of records at the 2008 Olympics, officials judged that suits made from such non-textile material gave an unfair edge and banned them, ruling that competition suits must be woven fabric.

Genuine denticle copying shows up elsewhere. Coatings that mimic a shark's ridged scales let cargo ships slide through water with less friction, trimming fuel use. Since global shipping burns more fuel than many entire countries, even a small cut adds up to a serious dent in emissions.