This plate is the simplest in terms of pictorial elements and offers very few alterations between the first and posterior states, indicating Piranesi's satisfaction with the results achieved already in the first edition. The colossal wheels that cover more than half of the illustration can be interpreted as parts of the hull of a large ship, destroyed and abandoned just like so many others throughout the Carceri. Disposed at the top of a stone portal, the hull still carried fragments of the beams that once supported the ship’s decks. Following the motif of the trophies of the previous plates, Piranesi depicted the fragments of the enormous hull as a colossal naval trophy, closing the sequence of direct references to these elements.
The changes between the editions of the late 1750s and 1761 consist, if not exclusively, to the addition of the wooden beams-like structure in the lower left of the plate. This object, in turn, be it shaped as a bracket or a crossbar, was repeatedly added to the plates of the Carceri series in the edition of 1761 and, therefore, deserves our special attention. Piranesi incorporated the piece prominently in the Title Page and in plates IV, VII, X, XIII, and XVI. He also added chunks of it in plates III, VI, VIII, XI, and XIV. The piece, already present since the first state of Plate XII, was unmistakably represented in the newly conceived plates II and V. In summary, Piranesi unquestionably attributed a great deal of symbolism to this form, which will be further explores in Plate XVI.
With the nautical visual repertoire he employs along the etchings of the Carceri, including the allusions to the naumachiae, Piranesi emphasizes the magnificence of Roman engineering and architecture. These theatrical spectacles emulating historical or mythological naval battles were enacted either for entertainment or for triumphal purposes in ancient Rome. The stage set for the naumachiae was a very complex and grandiose flooded structure whose idea is, to say the least, extravagant. Even by contemporary standards, the degree of technical effort required to make an artificial giant pool to reenact naval battles is enormous. It encompassed complex systems of aqueducts and sewers to bring the water in, flood the area, and drain the water when done. Indisputably, the naumachiae demonstrated the technical capability of a sophisticated society.
With the scale of the ambiguous wheels in plate IX, Piranesi also alludes to the wooden structures that precede the construction of bridges, aqueducts, or sewers. These were among the architectural and engineering Roman achievements that fascinated Piranesi the most. His enthusiasm with promoting the extraordinary degree of development of the Roman construction technology, especially before Greek influence, is decisive to understand the Carceri.
Piranesi borrowed the concept of Roman magnificence from Livy. In Ab urbe condita libri ("Books from the Founding of the City," or simply "History of Rome"), Livy had already claimed the romana magnificentia through the examples of the temple of Capitoline Jupiter, the Circus Maximus, and the Cloaca Maxima, built as early as the sixth century BCE. This was a robust argument Piranesi employed in many of his publications in favor of Roman superiority. Additionally, he had the opportunity to witness the discovery of an underground section of the Cloaca in 1742 in Rome. The remains must have greatly impacted the young Piranesi, that produced several etchings registering his own observations of the impressive ancient sewage system.
After entering the stone portal represented in the center of this plate, Piranesi takes us to contemplate several port-like spaces in the following plates until finally ending his journey in plate XVI.