Why is ship's bottom painted red ?

Question

seems like most of the ship do have so..

Answer 1

You have had a good answer, and I cannot resist this.

They are not painted red, but if you butt was left in water for that long it would get red too!

Answer 2

A couple answers are nuts...James is really good so is the one about red lead.

Petit Trinidad is a great paint. It is derived and reformulated  from one of the real old school and lead toxic paints called Red Hand.

Most commercial ships still have the toxic red lead paint on them...It is virtually insoluable in water once cured. The danger is in it's application and skin exposure and careless discard of unused product or removed product.

As mentioned by James...retail paint has seen it replaced with copper due to it's good anti-fouling properties and reduced toxicity.

Here's a referance:

http://en.wikipedia.org/wiki/Red_lead

Answer 3

I don't remember the exact terminology, but it has something to do with keeping the barnacles from growing on it.

Answer 4

Ships bottoms are not always red. Though in a lot cases it is. This is the color of the lead based anti fouling paint used for years to kill barnacles that try to attach themselves to a ships bottom. Other colors i have seen is green and blue. These bright colors also tell crews when there ship is over loaded as the paint only covers the bottom up to the waterline.

Answer 5

The paint is actually red lead and helps protect the hull from barnacles and such.

Answer 6

Anti-fouling paint (The paint on the bottom of boats and ships) is composed of either Cuprous Oxide (a form of copper) or Thiocyinate (sp?) a tin based compound.  As of 6 or 7 years ago the Thiocyinate paints started to become illegal because they kill more than the barnacles that they were intended to kill.  That leaves the Cuprous Oxide paints as the only anti-fouling paint left.  The red paints have the highest amount of copper in them.  Typical concentration is about 56% for Trinidad, a popular brand.  The same paint but in blue, green or white ranges from 38% to 48% concentration of Cuprous Oxide.  Since that is the active ingredient that kills the barnacles that slow down the ship and make it burn more fuel in the process, it just makes sense to paint it red and have it last a little longer as a haulout and repaint can cost thousands of dollars to the shipping company, not only to actually haul and paint the ship but the loss of a cargo carrying opportunity.  I know this answers your questions.  Sorry for the tremendously long run on sentence.

Answer 7

Most ship have a tabasco mixture on the bottom to keep barnacles from sticking to them

Answer 8

Red is the most common colour for antifouling paint used for ships to prevent algae and barnacles to adhere to the hull. The most common toxic used in these paint is Tin which will be forbidden in september 2008. Copper will take over as it is less toxic but slightly less effective.