The imperial Roman navy has attracted far less research than the legions and there are very few pieces of evidence that have survived to give us a truly accurate view of the ships. For those readers keen to read more about the navy I suggest obtaining a brief overview from Peter Connolly's excellent Greece and Rome at War. Beyond that there is a hard-to-find but very worthy read in Chester Starr's The Imperial Roman Navy.
There are a few conscious deviations from historical fact. Firstly, I have used the more recent terms of 'port' and 'starboard' to give our Roman sailors some nautical ambience. Secondly, the moving of the Ravenna fleet's base closer to the trading port. In reality the Roman naval bases were kept at a distance from the confusion of commercial shipping. However, I didn't want to tire Macro and Cato out in any long walks into town for a drink!
In addition to the two huge naval bases at Misenum and Ravenna there were additional flotillas scattered around the frontiers of the Empire. The fleets were charged with guarding the sea lanes and providing ad hoc military forces that could be landed wherever there was an urgent need for an armed presence.
Piracy was a fact of life for the seamen and merchants of the Ancient World. Indeed, in the first century BC pirates were boldly landing on the Italian peninsula to abduct travellers on the Appian Way. This hubristic attitude reached its zenith with a raid into the harbour at Ostia, in which the pirates burned a fleet of Roman warships. The audacious act proved to be one step too far for the Roman Senate, who hurriedly empowered Pompey the Great to raise a vast fleet to rid the sea of pirates. This he did in a whirlwind campaign of three months. Thereafter, pirates were forced to operate on a far smaller scale and men like Telemachus would represent an occasional threat to the sea lanes. The action between the Ravenna fleet and the ships of Telemachus would be dwarfed by the scale of the naval actions of the Punic and civil wars.
In this respect, the historic mission of the imperial navy was an unqualified success for nearly three centuries. As Chester Starr notes, their task was 'not to fight battles but to render them impossible'.
Despite Hollywood's representations of Roman galleys being propelled by chains of slaves, the reality is more likely to have been something along the lines of the Renaissance galleys, in which the men at the oars were a mixture of slaves and free men who were paid for their duties.