I've not heard of the
bottom paint about which you are asking.
However, I spent many years
commercial fishing on the BC coast and remember vividly slapping on gallons of red lead
paint, most of it on the
hull, but a fair bit over myself, back in the 50's, after caulking the entire
hull on 50-70 footer wooden vessels.
I understand the this is now forbidden by some governmental douchbag but believe me, it lasted well, kept the growth off the bottom and torridos on the out side of the hulls.
I should mention I am pushing 80 years old now and have not yet suffered any long term ill effects of my misspent youth!
Phil