US Navy ships: Blue below the waterline?

[Bill Nichols]

I saw these pics and noticed the ship is blue below the waterline. How long has this been the case?

Damage to USS Port Royal following Feb. 5 grounding about a half-mile south of Honolulu:

http://www.navy.mil/management/photodb/thumbnails/thumb_090219-N-4003L-001.jpg

http://www.navy.mil/management/photodb/thumbnails/thumb_090219-N-4003L-002.jpg

[SteamWake]

Since they started using pigmented zinc based antifouling paint?

No really thats a good question as these pigmanted paints are quite expensive as opposed to the non pigmented (orangish red) types.

Is there a reason?

[XabbaRus]

Because the CNO's granddaughter thinks its purtty....:haha:

[Digital_Trucker]

:hmmm: Torpedo camouflage? Perhaps some politicians brother-in-law owns the paint manufacturer? So the terrorist divers can't find the boat to plant the explosives? So Greenpeace can complain about fish running into the boat because they couldn't see it? So drug smuggling submarines will run into it and be captured?

[AVGWarhawk]

That color was on sale that day...:O:

[Etienne]

Colored anti-fouling paint has been available for quite some time, now. I worked on at least one (Commercial) ship that had a blue bottom, and I *think* a few that had a black bottom. Most commercial ships are red all over nowaday, so that's not a good indicator...

If companies are painting the bellies in company color, then it can't be THAT much more expensive than the traditional colors, I suppose.

Also, there were new international environmental regulations that came out relatively recently, regarding anti-fouling coating. I don't recall any of it (Anti-fouling paint is beyond my area of expertise), and I don't think it applies to the military, but it could be a factor in their decision.

Guessing out of my nether region : It could be a polymer-based antiadhesive coating, or something of the kind.