Black paint or ‘Boot-Topping’?
Ask military personnel what the difference between boot paint and boot-topping is, and they will tell you that they are pretty similar. Nonetheless, boot-topping happens to be the black coating used between the deck and waterline. Made of sulfur or lime, it has a thick and liquid-like consistency. Civilians might not have the ability to distinguish between the two, but a soldier can figure it out. They can tell them apart even from a mile away!

Black Paint Or ‘Boot Topping’