Brass is a combination of copper and zinc and has been used for boats for hundreds of years, particularly in cladding hull bottoms to keep out teredo worms from timbers.
Though a reliable biocide, brass is more ideal for freshwater boats, which poses a problem for those operating in seawater. Many boatbuilders reject the use of brass fitting for tubes exposed to seawater because it can lead to failed plumbing, at the very least, or a sinking boat at the worst case scenario. For better and safer sea boats, makers opt for bronze tube than brass. Read more from this blog http://bit.ly/2lfPXX6