Google is our friend - you can find a short writeup about 40% down the page here:
http://www.gutenberg.org/files/31179/31179-h/31179-h.htmFTA
"The use of catamaran hulls, or “double-hulls,” has been periodically popular with ship designers since the time of Charles II of England. The earliest of such vessels known in the present day were four sloops or shallops designed 1673-1687 by Sir William Petty, who was an inventor in the field of naval architecture and received some attention from Charles II and from the Royal Society.
The first Petty experiment, the Simon & Jude, later called Invention I, was launched October 28, 1662. She was designed with two hulls cylindrical in cross section, each 2 feet in diameter, and 20 feet long. A platform connected the hulls, giving the boat a beam of a little over 9 feet. She had a 20-foot mast stepped on one of the crossbeams connecting the hulls, with a single gaff sail. In sailing trials she beat three fast boats: the King’s barge, a large pleasure boat, and a man-of-war’s boat. This [Pg 153]“double-bottom,” also called a “sluiceboat” or “cylinder,” was later lengthened at the stern to make her 30 feet overall."
Interesting. Almost fits the B-Class dimensions
