It's a good one to have on DVD (or BluRay, that's probably still avaialble too), but it's a work of historical fiction, based on a much more detailed work of historical fiction. The Caligula anecdote about the shells... there's a scene in the miniseries about that (he arrives back in Rome with booty from "Neptune"), but that's based on an ancient anecdote, Caligula gathered shells from the North Sea coast of the mainland I believe it was. As an emperor, he was ****ty, but wow, in just those relatively few years he had a temple built to himself that featured 200 ton single-piece columns quarried in Egypt and brought to Rome by ship. He also had one of the largest obelisks in Egypt brought to Rome in one piece -- a special ship was built to haul that, and it was a tourist attraction in its own right. Claudius had it repurposed as a form to pour the concrete mole at the end of a great pier in his all-season port. The ship itself may actually still exist, upright, buried, and now somewhat far from the sea. If the wood is gone, a negative image of it in concrete may still exist. And there are, or rather were, the Nemi ships: