Leonardo da Vinci sketched a life buoy as a rescue device for a person falling into water.
The concept was designed to provide flotation and help keep a person at the surface. It belongs to Leonardo’s group of water-related inventions, which also included diving equipment and machines for canal transport.
A buoy is different from an anchor: an anchor is meant to hold a vessel or object in place, while a life buoy is intended to support a person in the water. It is also simpler than a diving bell, which creates an air space for underwater work.
Leonardo’s sketch shows that his engineering interests included safety as well as military technology and transport. The design was an early flotation concept, not evidence that modern standardized rescue rings already existed in his time.