If you ever needed incentive to keep your hull clean, an article in this week's Marine Corps Times has the reasons why. Or if you don't have a boat in the water, you can amaze your friends by reciting this trivia. Of course this is all about Navy ships, but I guess it apples to all vessels.
Clumps of barnacles can reduce vessel speed ben 10%.
Barnacles increase fuel consumption by 40%.
Barnacles cost the Navy about $500 million per year for extra fuel and maintenance.
The tensile strength of a barnacle's underwater -curing cement is 5000 psi.
There are 1400 species of barnacles world wide.
For 25 years the Navy has been trying to find a better way to repel barnacles that also meets environmental standard. They are now looking at a "hydrogel" material that will act as a slippery sealant.