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A ship’s fuel consumption can be reduced by about 20 per cent by designing it in such a manner that it exudes slime from its hull, according to a whale-inspired Indian researcher.

Rahul Ganguli of Teledyne Scientific in Thousand Oaks, California, says that the slime would form a gelatinous skin that continually sloughs off, taking with it the barnacles and other marine life forms that cause energy-sapping drag by accumulating on the ships’ underside.

He and his colleagues are currently testing the idea as part of a research project, being financed by the US Department of Defense.

His plan is to cover the outer layer of a ship in a metal mesh, beneath which is a regular pattern of holes that exude a sticky, biosafe chemical that becomes more viscous on contact with seawater.

The secretion oozing out of the pores fills the gap in the mesh and pools on top to form a viscous skin coating the entire hull that steadily wears away, taking with it any life that has gained a foothold. It is then replaced by new slime from below.

So far, Ganguli has tested the idea with two chemicals used on oil rigs—one used to thicken seawater to force open rock formations and the other to firm up acid used to dissolve rocks.

‘We think they will be safe for marine life,’ New Scientist magazine quoted him as saying.

Naval architect Peilin Zhou, at the University of Strathclyde in Glasgow, UK, feels that making this idea work would be lucrative.

‘If you do not have to bring the vessel to dry dock it would save a lot of money,’ Zhou says.

The journal reports that Ganguli’s idea is inspired by the skin of the long-finned pilot whale, Globicephala melas, the surface of which is criss-crossed with a network of nano-scale canals too small for any barnacle larvae to gain any purchase.

In a paper published in Marine Biology in 2002, Christoph Baum at Hannover School of Veterinary Medicine in Germany reported that the canals are filled with a gel of enzymes that destroy proteins on the surface of bacteria and algae.

Ganguli is presently trying to make a ship’s hull perform a similar self-cleaning trick.