According to Herodotos (6.15.2), the 100 Chiot triremes at Lade in 494 BC each carried 40 picked hoplites serving as epibatai Herodotos (7.184.2) mentions that Persian triremes carried, in addition to native marines, 30 additional fighting men who were Persians, Medes or Sakai, the last of whom were a nomadic people of central Asia, highly valued for their archery skills. Every Persian ship was supplied by Persian subjects, including Phoenicians, Egyptians, Carians, Cypriots and Greeks, among others. The non-seafaring Persians supplied only admirals and marines. The last were probably on board to ensure the loyalty of the ship's company and for that reason they were undoubtedly carried in battle.
The ten epibatai on an Athenian trireme had the highest status in the ship after the trierarchos. They are mentioned second in the Decree of Themistokles, and this is the position they occupy in the 4th-century crew lists (IG 22 1951.79-82). Thucydides notes that they joined the trierarchos in pouring libations at the ceremonial departure of the Sicilian expedition (6.32.1).
One reason for the Athenian practice of taking only a few hoplites on deck to serve as marines was that the crew's pulling efficiency was seriously jeopardized if there were too many people moving about topside. Such movement inevitably caused the ship to roll. Under oar, therefore, the epibatai had to be seated (Thucydides 7.67.2), and the procedure appears to have been to keep them centred on the middle line of the ship. Once the vessel had stopped to board an enemy vessel, the epibatai would leap up to fight once the ships grappled. In his speech before the final sea battle in the Great Harbour at Syracuse, the Athenian commander Nikias revealed another reason: 'Many archers and javelineers will be on deck and a mass of hoplites, which we would not employ if we were fighting a battle in the open sea, because they would hinder us through the weight of the ships in exercising our skill.' (Thucydides 7.62.2) Weight, particularly on deck, prevented the triremes doing what they did best, namely, conducting the tactical manoeuvres in which speed and agility were essential.
The four toxotai were distinct from the ten epibatai, namely they were not carried on deck. An inscription (IG I2 950.137), dated to 412/411 BC, gives them a descriptive adjective, paredroi, meaning 'sitting beside'. It seems that they were posted in the stern beside the trierarchos and kubernetes and acted as their bodyguard in action. The helmsman would certainly have been vulnerable and would have needed protection, being too busy to defend himself. The Athenian playwright Euripides (Iphigenia among the Taurians 1377) talks of archers stationed in the stern, giving covering fire during an embarkation.