Leonardo da Vinci sketched a catamaran with two separate hulls for greater stability.
His notebooks contain designs for boats and naval devices, including a vessel formed from two parallel hulls connected by a deck. This arrangement gives a craft a wide base of support and is the defining feature of a catamaran. Leonardo’s interest was practical: a stable, broad vessel could be useful for transport and work on water.
Leonardo did not invent the general concept of twin-hulled boats. Multihull craft existed in other maritime traditions long before his drawings, especially in the Pacific and Indian Ocean regions. His contribution was to record and develop mechanical designs within Renaissance Europe.
The sketch should not be confused with Leonardo’s proposed submarine or diving equipment. Those designs concern underwater operation, whereas the two-hulled craft is a surface vessel. Modern catamarans may use sails or engines, but Leonardo’s drawing does not represent a modern powered boat.