Leonardo da Vinci studied a double-hull design intended to reduce the danger of flooding.
A double hull places a second layer of structure inside or outside the main hull, creating a space between the two surfaces. If the outer layer is damaged, the inner hull can continue to hold water out. Leonardo’s notebooks contain ship and naval-engineering studies that explored ways to make vessels stronger and more resistant to damage.
The concept is different from a catamaran, which has two separate hulls that both support the vessel in the water. A double hull is a protective construction arrangement within one ship design.
Modern tankers commonly use double hulls to reduce pollution and cargo-tank damage after collisions or groundings. Leonardo’s study did not create the modern shipping standard, but it illustrates his early interest in compartmentalization and structural safety.