On Jan 24, 4:22 pm, "Ellen MacArthur"
wrote:
"katy" wrote

It's a shark....haven't you ever seen a hammerhead? I thought you were in Florida? Hammerhead sharks have sort of like fins on the sides of their heads. The eyes
are out on the end of them. But their heads are still streamlined if you look at them
from the front. They are like streamlined stalks or wings. It's sorta like having an
extra set of fins like porpoises have on their sides where the arms used to be before
they went back into the sea and evolved. But hammerheads have them on their heads.

Cheers,
Ellen

Shark skin saves naval industry money

Covering ship hulls with artificial shark skin could help ships sailing
smoothly. The growth of marine organisms such as barnacles on ship
hulls is a major cause of increased energy costs in the naval industry.
Shark skin offers a structural design that prevents this so called
'bio-fouling'.
Ralph Liedert from the University of Applied Sciences, Bremen, Germany,
is presenting his work on the application of artificial shark skin in a
new anti-fouling strategy at the Society for Experimental Biology
Annual Main Meeting in Barcelona [session A7.66].

Shark skin comprises scales that can flex individually from each other.
Liedert produced a synthetic shark skin of elastic silicone, which has
a significantly decreased contact surface.

This reduced contact surface makes it harder for barnacles to attach,
and reduces fouling by 67%. When applied to the ship hull, this
artificial surface enables ships to ´self-clean´, and a speed of 4-5
knots would remove all organisms attached with little adhesion.

Until recently, paints containing a biocide were used to prevent growth
on submerged surfaces, but these were banned because of the the toxic
effect of the highly toxic and unspecific biocide component on marine
life.

As barnacles, mussels and algae cause up to 15% increase in the drag
resistence of ships, this research is providing an alternative
anti-fouling strategy of great importance.

Joe