In the ancient navies, crews were composed not of galley slaves but of free men. In the Athenian case in particular, service in ships was the integral part of the military service provided by the lower classes, the thētai, although metics and hired foreigners were also accepted. Although it has been argued that slaves formed part of the rowing crew in the Sicilian Expedition, a typical Athenian trireme crew during the Peloponnesian War consisted of 80 citizens, 60 metics and 60 foreign hands. Indeed, in the few emergency cases where slaves were used to crew ships, these were deliberately set free, usually before being employed. For instance, the tyrant Dionysius I of Syracuse once set all slaves of Syracuse free to man his galleys, employing thus freedmen, but otherwise relied on citizens and foreigners as oarsmen.
In the Athenian navy, the crews enjoyed long practice in peacetime, becoming skilled professionals and ensuring Athens’ supremacy in naval warfare. The rowers were divided according to their positions in the ship into thranitai, zygitai, and thalamitai. According to the excavated Naval Inventories, lists of ships’ equipment compiled by the Athenian naval boards, there were:
62 thranitai in the top row (thranos means “deck”). They rowed through the parexeiresia, an outrigger which enabled the inclusion of the third row of oars without significant increase to the height and loss of stability of the ship. Greater demands were placed upon their strength and synchronization than on those of the other two rows.
54 zygitai in the middle row, named after the beams (zygoi) on which they sat.
54 thalamitai or thalamioi in the lowest row, (thalamos means “hold”). Their position was certainly the most uncomfortable, being underneath their colleagues and also exposed to the water entering through the oarholes, despite the use of the askōma, a leather sleeve through which the oar emerged.
Most of the rowers (108 of the 170 – the zygitai and thalamitai), due to the design of the ship, were unable to see the water and therefore, rowed blindly, therefore coordinating the rowing required great skill and practice. It is not known exactly how this was done, but there are literary and visual references to the use of gestures and pipe playing to convey orders to rowers. In the sea trials of the reconstruction Olympias, it was evident that this was a difficult problem to solve, given the amount of noise that a full rowing crew generated. In Aristophanes’ play The Frogs two different rowing chants can be found: “ryppapai” and “o opop”, both corresponding quite well to the sound and motion of the oar going through its full cycle.