The 1ar folio part of the Codex Atlanticus, dated between 1503 and 1505, features a clearly visible image on the top right corner, though on the same page there are also many sketches that are open to various interpretations. The most recent one, by the Leonardo3 studies centre, offers a new interpretation: a mighty ship equipped with sixteen cannons.
Machines
Multi Cannon Gunship
Codex Atlanticus, folio 1ar (1503-1505)