Dreadnought boot topping

Google Images 'HMS DREADNOUGHT'

You will find several contemporary B&W photos which are inconclusive as to the colors at the waterline.  However you will also find some contemporary watercolors and colored post cards which appear to show a black waterline.  Add to that Robert's Anatomy of the Ship also shows a black waterline.   You are pretty much free to paint the waterline as you choose and dare anyone to tell you that you are wrong.  

Black boot topping came into place around the turn of the last century and into the teens as oil replaced coal as fuel.  Oil scum on the harbor's surface created a 'ring around the tub' appearance that coal dust and wood ash did not.    It was more persistent and didn't just wash away.    In order to keep a smart looking ship,  captains went to painting a black ring at the design waterline +/- a couple of inches to hide the scum.

Also during the Victorian period there were several navies which painted colored "cheat lines" at the waterline which were largely decorative.     I've seen paintings of bright red and white lines on black hulls.  Pretty but not as effective in hiding scum

Depending on the navy - the boot stripe might have a slight taper to it; being slightly higher at the bow than at the stern.  Many navies have painting regulation which state the height of the boot stripe at amidships is X percenetage of the freeboard height.  I'm most familiar with the USCG paint regs, and the boot topping height is proportionaL to the length of the vessel.  On cutters over 150 feet long, the height of the boot stripe is 1/8 of the freeboard distance; at the bow the height is 1.33 the amidships height; at the stern, it's .66 the amidships height.  On the last cutter I served on, the boot stripe was 4 feet high at the bow, 3 feet at amidships, and 2 feet at the stern.  The lower edge was equal to the light load water line of the cutter.

Thanks, Guys.  Sounds like I should use the black boot topping on the Dreadnought.

Interestingly, I googled BT and many of the dictionary definitions defined it as any anti-fouling paint or treatment on the hull below the waterline. It looks like the definition changed this century to the modern definition of the black line terminating those bottom coatings.

A boat is not the same without the boot stripe.