kathy wrote:

This is a fascinating article.

According to the Navy, algae and barnacles on hulls increase drag,
slowing ships and reducing fuel efficiency. Of the $550 million to $600
million the Navy spends annually on powering its ships and submarines,
at least $50 million stems directly from fouling-related increased
drag....

It is fascinating. That figure only looks at the immediate cost of fuel.
Then there's the cost of regular dry-docking for the addition of expensive
anti-fouling paints & the completely hidden costs to the environment of the
use of anti-fouling paints. Anybody involved with sea-going vessels has
been searching for this sort of solution.
--
derek