Illustration of Da Vinci's Dredge Machine. Leonardo di ser Piero da Vinci (April 15, 1452 - May 2, 1519) was an Italian Renaissance polymath: painter, sculptor, architect, musician, mathematician, engineer, inventor, anatomist, geologist, cartographer, botanist, and writer. He has often been described as the archetype of the Renaissance Man, one of the greatest painters of all time and perhaps the most diversely talented person ever to have lived. Dredging is an excavation activity or operation usually carried out at least partly underwater, in shallow seas or fresh water areas with the purpose of gathering up bottom sediments and disposing of them at a different location. This technique is often used to keep waterways navigable.