The first coating for this purpose is usually dry red lead mixed on the spot with raw linseed oil and, in the opinion of the author, nothing better can be devised. However next to the red lead a non-corrosive coating is required, that will, in a measure, not only protect the red lead from being affected by the sea water, but also give a solid base for the anti-fouling coating. This must be a paint, that is neutral and impervious, free of pinholes and other imperfections, and the very best for the purpose, that can be produced is of the following composition: 50 lbs. sublimed blue lead, 12 1/2 lbs. zinc oxide, (American), 17 1/2 lbs. English cliffstone Paris white, ground in 20 lbs. heavy bodied linseed oil, (oxidized oil without drier) to form the base. One hundred pounds of this base, that may be colored with pure Indian red to make a sort of chocolate color is thinned with equal portions of raw linseed oil, turpentine and hard gum varnish to brushing consistency.