Leonardo da Vinci sketched a catamaran, a boat with two parallel hulls joined by a deck or frame. His design is one of the early documented examples of a twin-hull vessel in European engineering history.
A twin-hull arrangement can improve stability because the hulls spread buoyancy across a wider footprint. Leonardo’s concept was associated with transporting people or goods on water, and its broad platform could offer more usable space than a narrow single-hull boat.
The word catamaran is much older than Leonardo. It comes from the Tamil word kattumaram, referring to a type of tied-together raft or boat used in South India. Modern catamarans range from small sailing craft to large commercial ferries.
Leonardo’s sketch should not be confused with a modern high-speed catamaran. He did not have contemporary materials, engines, or hydrodynamic knowledge. The significance of the drawing is the early use of separated hulls to combine flotation and stability.