Amphibious vessel with treaded wheels

The boat had the capacity, when needed, of transforming into a hybrid vehicle capable of passing over sandy dry portions of the river course, as well as over deposits of mud that accumulated in the river beds during dry months. The outer wheels, similar to those of a modern tractor, made it possible for the vehicle to advance by gripping onto the sludgy ground.

Francesco likely took inspiration from the boats used in the Naumachiae, performances dating from classical Greek and Roman times, in which actual naval battles were staged for entertainment. Those boats were indeed equipped with wheels that allowed the vessels to be easily transported into the arenas.